{"segment":[{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"\u0110\u1ec1 chung cho hai c\u00e2u","temp":"fill_the_blank","correct":[[["2"],["1"],["5"],["3"],["5"],["3"],["1"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":" <span class='basic_left'> Ng\u01b0\u1eddi ta th\u1ed1ng k\u00ea s\u1ed1 h\u1ecdc sinh c\u1ee7a $20$ l\u1edbp h\u1ecdc trong m\u1ed9t tr\u01b0\u1eddng trung h\u1ecdc c\u01a1 s\u1edf v\u00e0 thu \u0111\u01b0\u1ee3c b\u1ea3ng k\u1ebft qu\u1ea3 sau: <br\/> <table><tr><th>34<\/th><th>30<\/th><th>34<\/th><th>33<\/th><th>30<\/th><th>32<\/th><th>34<\/th><th>35<\/th><th>34<\/th><th>35<\/th><\/tr><tr><td>34<\/td><td>33<\/td><td>32<\/td><td>32<\/td><td>32<\/td><td>35<\/td><td>31<\/td><td>32<\/td><td>33<\/td><td>36<\/td><\/tr><\/table> <br\/> <b>C\u00e2u 1.<\/b> \u0110i\u1ec1n v\u00e0o c\u00e1c \u00f4 tr\u1ed1ng trong b\u1ea3ng \u201ct\u1ea7n s\u1ed1\u201d sau: <br\/> <table><tr><th>S\u1ed1 h\u1ecdc sinh $(x)$<\/th><th>30<\/th><th>31<\/th><th>32<\/th><th>33<\/th><th>34<\/th><th>35<\/th><th>36<\/th><\/tr><tr><td>T\u1ea7n s\u1ed1 $(n)$<\/td><td>_input_<\/td><td>_input_<\/td><td>_input_<\/td><td>_input_<\/td><td>_input_<\/td><td>_input_<\/td><td>_input_<\/td><\/tr><\/table> <\/span>","explain":"<span class='basic_left'> T\u1eeb b\u1ea3ng s\u1ed1 li\u1ec7u ban \u0111\u1ea7u \u0111\u00e3 cho ta c\u00f3 b\u1ea3ng \u201ct\u1ea7n s\u1ed1\u201d t\u01b0\u01a1ng \u1ee9ng l\u00e0: <br\/> <table><tr><th>S\u1ed1 h\u1ecdc sinh $(x)$<\/th><th>30<\/th><th>31<\/th><th>32<\/th><th>33<\/th><th>34<\/th><th>35<\/th><th>36<\/th><\/tr><tr><td>T\u1ea7n s\u1ed1 $(n)$<\/td><td>2<\/td><td>1<\/td><td>5<\/td><td>3<\/td><td>5<\/td><td>3<\/td><td>1<\/td><\/tr><\/table> <br\/> <span class='basic_pink'> V\u1eady c\u00e1c s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o c\u00e1c \u00f4 tr\u1ed1ng l\u1ea7n l\u01b0\u1ee3t l\u00e0 $2;1;5;3;5;3;1.$<\/span><\/span>"}]}],"id_ques":1011},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"\u0110\u1ec1 chung cho hai c\u00e2u","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":" <span class='basic_left'>Ng\u01b0\u1eddi ta th\u1ed1ng k\u00ea s\u1ed1 h\u1ecdc sinh c\u1ee7a $20$ l\u1edbp h\u1ecdc trong m\u1ed9t tr\u01b0\u1eddng trung h\u1ecdc c\u01a1 s\u1edf v\u00e0 thu \u0111\u01b0\u1ee3c b\u1ea3ng k\u1ebft qu\u1ea3 sau: <br\/> <table><tr><th>34<\/th><th>30<\/th><th>34<\/th><th>33<\/th><th>30<\/th><th>32<\/th><th>34<\/th><th>35<\/th><th>34<\/th><th>35<\/th><\/tr><tr><td>34<\/td><td>33<\/td><td>32<\/td><td>32<\/td><td>32<\/td><td>35<\/td><td>31<\/td><td>32<\/td><td>33<\/td><td>36<\/td><\/tr><\/table> <br\/> <b>C\u00e2u 2.<\/b> M\u1ed1t c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0 32. <\/span>","select":["\u0110\u00fang","Sai"],"explain":"<span class='basic_left'> Theo c\u00e2u 1, ta c\u00f3 b\u1ea3ng ''t\u1ea7n s\u1ed1'' nh\u01b0 sau: <br\/><table><tr><th>S\u1ed1 h\u1ecdc sinh $(x)$<\/th><th>30<\/th><th>31<\/th><th>32<\/th><th>33<\/th><th>34<\/th><th>35<\/th><th>36<\/th><\/tr><tr><td>T\u1ea7n s\u1ed1 $(n)$<\/td><td>2<\/td><td>1<\/td><td>5<\/td><td>3<\/td><td>5<\/td><td>3<\/td><td>1<\/td><\/tr><\/table> <br\/> Nh\u00ecn v\u00e0o b\u1ea3ng \u201ct\u1ea7n s\u1ed1\u201d ta th\u1ea5y hai gi\u00e1 tr\u1ecb $32$ v\u00e0 $34$ \u0111\u1ec1u c\u00f3 t\u1ea7n s\u1ed1 l\u1edbn nh\u1ea5t l\u00e0 $5.$ <br\/> Do \u0111\u00f3, m\u1ed1t c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0 $32$ v\u00e0 $34.$<br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 Sai.<\/span> <br\/> <b>L\u01b0u \u00fd:<\/b> M\u1ed1t c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0 gi\u00e1 tr\u1ecb c\u00f3 t\u1ea7n s\u1ed1 l\u1edbn nh\u1ea5t. <br\/> M\u1ed9t d\u1ea5u hi\u1ec7u c\u00f3 th\u1ec3 c\u00f3 nhi\u1ec1u m\u1ed1t. <\/span>","column":2}]}],"id_ques":1012},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"\u0110\u1ec1 chung cho hai c\u00e2u","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" <span class='basic_left'>Cho d\u00e3y gi\u00e1 tr\u1ecb trong b\u1ea3ng sau: <br\/> <table><tr><th>17<\/th><th>20<\/th><th>18<\/th><th>18<\/th><th>19<\/th><th>17<\/th><th>22<\/th><th>30<\/th><th>18<\/th><th>21<\/th><\/tr><tr><td>17<\/td><td>32<\/td><td>19<\/td><td>20<\/td><td>26<\/td><td>18<\/td><td>21<\/td><td>24<\/td><td>19<\/td><td>21<\/td><\/tr><tr><td>28<\/td><td>18<\/td><td>19<\/td><td>31<\/td><td>26<\/td><td>26<\/td><td>31<\/td><td>24<\/td><td>24<\/td><td>22<\/td><\/tr><\/table> <br\/> <b>C\u00e2u 1.<\/b> L\u1eadp b\u1ea3ng \u201ct\u1ea7n s\u1ed1\u201d v\u00e0 t\u00ednh s\u1ed1 trung b\u00ecnh c\u1ed9ng c\u1ee7a d\u1ea5u hi\u1ec7u. <br\/> S\u1ed1 trung b\u00ecnh c\u1ed9ng c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0: <\/span>","select":["A. $22,2$","B. $25$","C. $26,43$","D. $28$"],"explain":"<span class='basic_left'> Ta c\u00f3 b\u1ea3ng \u201ct\u1ea7n s\u1ed1\u201d t\u01b0\u01a1ng \u1ee9ng l\u00e0: <br\/> <table><tr><th>Gi\u00e1 tr\u1ecb $(x)$<\/th><th>T\u1ea7n s\u1ed1 $(n)$<\/th><th>C\u00e1c t\u00edch $(x.n)$<\/th><\/tr><tr><td>17<\/td><td>3<\/td><td>51<\/td><\/tr><tr><td>18<\/td><td>5<\/td><td>90<\/td><\/tr><tr><td>19<\/td><td>4<\/td><td>76<\/td><\/tr><tr><td>20<\/td><td>2<\/td><td>40<\/td><\/tr><tr><td>21<\/td><td>3<\/td><td>63<\/td><\/tr><tr><td>22<\/td><td>2<\/td><td>44<\/td><\/tr><tr><td>24<\/td><td>3<\/td><td>72<\/td><\/tr><tr><td>26<\/td><td>3<\/td><td>78<\/td><\/tr><tr><td>28<\/td><td>1<\/td><td>28<\/td><\/tr><tr><td>30<\/td><td>1<\/td><td>30<\/td><\/tr><tr><td>31<\/td><td>2<\/td><td>62<\/td><\/tr><tr><td>32<\/td><td>1<\/td><td>32<\/td><\/tr><tr><td><\/td><td>$N=30$<\/td><td>T\u1ed5ng: $666$<\/td><\/tr><\/table> <br\/> S\u1ed1 trung b\u00ecnh c\u1ed9ng c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0: <br\/> $\\overline{X}=\\dfrac{666}{30}=22,2$ <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 A.<\/span> <\/span>","column":4}]}],"id_ques":1013},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"\u0110\u1ec1 chung cho hai c\u00e2u","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" <span class='basic_left'>Cho d\u00e3y gi\u00e1 tr\u1ecb trong b\u1ea3ng sau: <br\/> <table><tr><th>17<\/th><th>20<\/th><th>18<\/th><th>18<\/th><th>19<\/th><th>17<\/th><th>22<\/th><th>30<\/th><th>18<\/th><th>21<\/th><\/tr><tr><td>17<\/td><td>32<\/td><td>19<\/td><td>20<\/td><td>26<\/td><td>18<\/td><td>21<\/td><td>24<\/td><td>19<\/td><td>21<\/td><\/tr><tr><td>28<\/td><td>18<\/td><td>19<\/td><td>31<\/td><td>26<\/td><td>26<\/td><td>31<\/td><td>24<\/td><td>24<\/td><td>22<\/td><\/tr><\/table> <br\/> <b>C\u00e2u 2.<\/b> M\u1ed1t c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0: <\/span>","select":["A. $18$","B. $21$","C. $24$","D. $26$"],"explain":"<span class='basic_left'> Ta c\u00f3 b\u1ea3ng \u201ct\u1ea7n s\u1ed1\u201d l\u00e0: <br\/> <table><tr><th>Gi\u00e1 tr\u1ecb $(x)$<\/th><th>T\u1ea7n s\u1ed1 $(n)$<\/th><th>C\u00e1c t\u00edch $(x.n)$<\/th><\/tr><tr><td>17<\/td><td>3<\/td><td>51<\/td><\/tr><tr><td>18<\/td><td>5<\/td><td>90<\/td><\/tr><tr><td>19<\/td><td>4<\/td><td>76<\/td><\/tr><tr><td>20<\/td><td>2<\/td><td>40<\/td><\/tr><tr><td>21<\/td><td>3<\/td><td>63<\/td><\/tr><tr><td>22<\/td><td>2<\/td><td>44<\/td><\/tr><tr><td>24<\/td><td>3<\/td><td>72<\/td><\/tr><tr><td>26<\/td><td>3<\/td><td>78<\/td><\/tr><tr><td>28<\/td><td>1<\/td><td>28<\/td><\/tr><tr><td>30<\/td><td>1<\/td><td>30<\/td><\/tr><tr><td>31<\/td><td>2<\/td><td>62<\/td><\/tr><tr><td>32<\/td><td>1<\/td><td>32<\/td><\/tr><tr><td><\/td><td>$N=30$<\/td><td>T\u1ed5ng: $666$<\/td><\/tr><\/table> <br\/> Ta th\u1ea5y gi\u00e1 tr\u1ecb $18$ c\u00f3 t\u1ea7n s\u1ed1 l\u1edbn nh\u1ea5t l\u00e0 $5.$ <br\/> Do \u0111\u00f3, m\u1ed1t c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0 $18$ <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 A.<\/span> <\/span>","column":4}]}],"id_ques":1014},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["1"],["30"],["4"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":" <span class='basic_left'> Cho b\u1ea3ng s\u1ed1 li\u1ec7u \u0111i\u1ec1u tra v\u1ec1 s\u1ed1 \u0111i\u1ec3m c\u1ee7a $50$ h\u1ecdc sinh nh\u01b0 sau: <br\/> <table><tr><th>Gi\u00e1 tr\u1ecb $(x)$<\/th><th>T\u1ea7n s\u1ed1 $(n)$<\/th><\/tr><tr><td>$x-10$<\/td><td>2<\/td><\/tr><tr><td>$11-20$<\/td><td>4<\/td><\/tr><tr><td>$21-y$<\/td><td>12<\/td><\/tr><tr><td>$31-40$<\/td><td>28<\/td><\/tr><tr><td>$41-50$<\/td><td>$z$<\/td><\/tr><\/table> <br\/> T\u00ecm gi\u00e1 tr\u1ecb c\u1ee7a $x;y;z.$ <br\/> <b> \u0110\u00e1p \u00e1n: <\/b> $x=\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}; y=\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{};z=\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}$ <\/span>","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> - T\u00ecm $z$ th\u00f4ng qua s\u1ed1 c\u00e1c gi\u00e1 tr\u1ecb c\u1ee7a d\u1ea5u hi\u1ec7u <br\/> Nh\u1eadn \u0111\u1ecbnh v\u1ec1 \u0111\u1eb7c \u0111i\u1ec3m c\u00e1c kho\u1ea3ng gi\u00e1 tr\u1ecb c\u1ee7a d\u1ea5u hi\u1ec7u \u0111\u1ec3 t\u00ecm $x;y$<br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> Theo b\u00e0i s\u1ed1 c\u00e1c gi\u00e1 tr\u1ecb l\u00e0 $50.$ <br\/> Do \u0111\u00f3, ta c\u00f3: <br\/> $\\begin{align} & 2+4+12+28+z=50 \\\\ & \\Rightarrow 46+z=50 \\\\ & \\Rightarrow z=50-46 \\\\ & \\Rightarrow z=4 \\\\ \\end{align}$ <br\/> Ta x\u00e9t \u1edf c\u1ed9t gi\u00e1 tr\u1ecb (d\u1ea1ng kho\u1ea3ng) th\u00ec c\u00f3 c\u00e1c kho\u1ea3ng: $11-20; 31-40;41-50.$ <br\/> C\u00e1c kho\u1ea3ng n\u00e0y \u0111\u1ec1u c\u00f3 s\u1ed1 cu\u1ed1i c\u00e1ch s\u1ed1 \u0111\u1ea7u $9$ \u0111\u01a1n v\u1ecb. <br\/> Do \u0111\u00f3, c\u00e1c kho\u1ea3ng $x-10$ v\u00e0 $21-y$ c\u0169ng c\u00f3 \u0111\u1eb7c \u0111i\u1ec3m t\u01b0\u01a1ng t\u1ef1 nh\u01b0 v\u1eady, t\u1ee9c l\u00e0 s\u1ed1 cu\u1ed1i c\u00e1ch s\u1ed1 \u0111\u1ea7u $9$ \u0111\u01a1n v\u1ecb. <br\/> Suy ra $x=10-9=1; y=21+9=30$ <br\/> V\u1eady $x=1;y=30; z=4$ <br\/> <span class='basic_pink'>V\u1eady c\u00e1c s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o c\u00e1c \u00f4 tr\u1ed1ng l\u1ea7n l\u01b0\u1ee3t l\u00e0 $1; 30$ v\u00e0 $4.$<\/span><\/span>"}]}],"id_ques":1015},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"\u0110\u1ec1 chung cho hai c\u00e2u","temp":"fill_the_blank","correct":[[["36"],["6"],["39"],["7"],["42"],["3"],["45"],["3"],["48"],["3"],["51"],["5"],["54"],["3"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":" <span class='basic_left'> S\u1ed1 c\u00e2n n\u1eb7ng c\u1ee7a $30$ h\u1ecdc sinh cho theo b\u1ea3ng sau: <br\/> <table><tr><th>46<\/th><th>35<\/th><th>51<\/th><th>48<\/th><th>46<\/th><th>50<\/th><th>36<\/th><th>39<\/th><th>40<\/th><th>55<\/th><\/tr><tr><td>44<\/td><td>54<\/td><td>35<\/td><td>40<\/td><td>49<\/td><td>35<\/td><td>41<\/td><td>38<\/td><td>51<\/td><td>54<\/td><\/tr><tr><td>36<\/td><td>38<\/td><td>43<\/td><td>51<\/td><td>39<\/td><td>38<\/td><td>47<\/td><td>50<\/td><td>43<\/td><td>37<\/td><\/tr><\/table> <br\/> <b> C\u00e2u 1. <\/b> D\u1ef1a v\u00e0o b\u1ea3ng tr\u00ean h\u00e3y \u0111i\u1ec1n v\u00e0o c\u00e1c \u00f4 tr\u1ed1ng \u0111\u1ec3 ho\u00e0n thi\u1ec7n b\u1ea3ng sau: <br\/> <table><tr><th>C\u00e2n n\u1eb7ng $(kg)$<\/th><th>Trung b\u00ecnh c\u1ed9ng c\u1ee7a kho\u1ea3ng $(kg)$<\/th><th>T\u1ea7n s\u1ed1<\/th><\/tr><tr><td>$35-37$<\/td><td>_input_<\/td><td>_input_<\/td><\/tr><tr><td>$38-40$<\/td><td>_input_<\/td><td>_input_<\/td><\/tr><tr><td>$41-43$<\/td><td>_input_<\/td><td>_input_<\/td><\/tr><tr><td>$44-46$<\/td><td>_input_<\/td><td>_input_<\/td><\/tr><tr><td>$47-49$<\/td><td>_input_<\/td><td>_input_<\/td><\/tr><tr><td>$50-52$<\/td><td>_input_<\/td><td>_input_<\/td><\/tr><tr><td>$53-55$<\/td><td>_input_<\/td><td>_input_<\/td><\/tr><\/table> <\/span>","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> T\u00ednh s\u1ed1 trung b\u00ecnh c\u1ed9ng c\u1ee7a t\u1eebng kho\u1ea3ng. S\u1ed1 \u0111\u00f3 ch\u00ednh l\u00e0 trung b\u00ecnh c\u1ed9ng c\u1ee7a gi\u00e1 tr\u1ecb l\u1edbn nh\u1ea5t v\u00e0 nh\u1ecf nh\u1ea5t c\u1ee7a kho\u1ea3ng. V\u00ed d\u1ee5 trung b\u00ecnh c\u1ed9ng c\u1ee7a kho\u1ea3ng $150-152$ l\u00e0 $151.$<br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> Ta c\u00f3 b\u1ea3ng \u0111i\u1ec1n \u0111\u1ea7y \u0111\u1ee7 nh\u01b0 sau: <br\/> <table><tr><th>C\u00e2n n\u1eb7ng $(kg)$<\/th><th>Trung b\u00ecnh c\u1ed9ng c\u1ee7a kho\u1ea3ng $(kg)$<\/th><th>T\u1ea7n s\u1ed1<\/th><\/tr><tr><td>$35-37$<\/td><td>36<\/td><td>6<\/td><\/tr><tr><td>$38-40$<\/td><td>39<\/td><td>7<\/td><\/tr><tr><td>41-43<\/td><td>42<\/td><td>3<\/td><\/tr><tr><td>$44-46$<\/td><td>45<\/td><td>3<\/td><\/tr><tr><td>$47-49$<\/td><td>48<\/td><td>3<\/td><\/tr><tr><td>$50-52$<\/td><td>51<\/td><td>5<\/td><\/tr><tr><td>$53-55$<\/td><td>54<\/td><td>3<\/td><\/tr><\/table> <br\/> <\/span>"}]}],"id_ques":1016},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"\u0110\u1ec1 chung cho hai c\u00e2u","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":" <span class='basic_left'>S\u1ed1 c\u00e2n n\u1eb7ng c\u1ee7a $30$ h\u1ecdc sinh cho theo b\u1ea3ng sau: <br\/> <table><tr><th>46<\/th><th>35<\/th><th>51<\/th><th>48<\/th><th>46<\/th><th>50<\/th><th>36<\/th><th>39<\/th><th>40<\/th><th>55<\/th><\/tr><tr><td>44<\/td><td>54<\/td><td>35<\/td><td>40<\/td><td>49<\/td><td>35<\/td><td>41<\/td><td>38<\/td><td>51<\/td><td>54<\/td><\/tr><tr><td>36<\/td><td>38<\/td><td>43<\/td><td>51<\/td><td>39<\/td><td>38<\/td><td>47<\/td><td>50<\/td><td>43<\/td><td>37<\/td><\/tr><\/table> <br\/> <b> C\u00e2u 2. <\/b> S\u1ed1 c\u00e2n n\u1eb7ng trung b\u00ecnh c\u1ee7a m\u1ed7i h\u1ecdc sinh l\u00e0: <\/span>","select":["A. $45\\,(kg)$","B. $44,3\\,(kg)$","C. $43,7\\,(kg)$","D. $48\\,(kg)$"],"explain":"<span class='basic_left'>Ta c\u00f3 b\u1ea3ng t\u00ednh s\u1ed1 c\u00e2n n\u1eb7ng trung b\u00ecnh c\u1ee7a m\u1ed7i h\u1ecdc sinh nh\u01b0 sau: <br\/> <table><tr><th>C\u00e2n n\u1eb7ng (kg)<\/th><th>Trung b\u00ecnh c\u1ed9ng c\u1ee7a kho\u1ea3ng (kg)<\/th><th>T\u1ea7n s\u1ed1<\/th><th>C\u00e1c t\u00edch<\/th><\/tr><tr><td>$35-37$<\/td><td>36<\/td><td>6<\/td><td>216<\/td><\/tr><tr><td>$38-40$<\/td><td>39<\/td><td>7<\/td><td>273<\/td><\/tr><tr><td>$41-43$<\/td><td>42<\/td><td>3<\/td><td>126<\/td><\/tr><tr><td>$44-46$<\/td><td>45<\/td><td>3<\/td><td>135<\/td><\/tr><tr><td>$47-49$<\/td><td>48<\/td><td>3<\/td><td>144<\/td><\/tr><tr><td>$50-52$<\/td><td>51<\/td><td>5<\/td><td>255<\/td><\/tr><tr><td>$53-55$<\/td><td>54<\/td><td>3<\/td><td>162<\/td><\/tr><tr><td><\/td><td><\/td><td>$N=30$<\/td><td>T\u1ed5ng: $1311$<\/td><\/tr><tr><td><\/td><td><\/td><td><\/td><td>$\\overline{X}=\\dfrac{1311}{30}=43,7$ <\/td><\/tr><\/table> <br\/> S\u1ed1 c\u00e2n n\u1eb7ng trung b\u00ecnh c\u1ee7a m\u1ed7i h\u1ecdc sinh l\u00e0 $43,7\\,(kg)$<br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 C.<\/span><\/span>","column":4}]}],"id_ques":1017},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["10"],["17"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":" <span class='basic_left'> Cho b\u1ea3ng s\u1ed1 li\u1ec7u sau: <br\/> <table><tr><th>Gi\u00e1 tr\u1ecb $(x)$<\/th><th>T\u1ea7n s\u1ed1 $(n)$<\/th><\/tr><tr><td>2<\/td><td>x<\/td><\/tr><tr><td>4<\/td><td>15<\/td><\/tr><tr><td>6<\/td><td>28<\/td><\/tr><tr><td>8<\/td><td>30<\/td><\/tr><tr><td>10<\/td><td>y<\/td><\/tr><tr><td><\/td><td>$N=100$<\/td><\/tr><\/table> <br\/> Bi\u1ebft s\u1ed1 c\u00e1c gi\u00e1 tr\u1ecb kh\u00f4ng nh\u1ecf h\u01a1n $6$ l\u00e0 $75.$ T\u00ecm gi\u00e1 tr\u1ecb c\u1ee7a $x;y.$ <br\/> <b> \u0110\u00e1p \u00e1n: <\/b> $x=\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}; y=\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}$ <\/span>","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> T\u00ecm $y$ t\u1eeb d\u1eef ki\u1ec7n: s\u1ed1 c\u00e1c gi\u00e1 tr\u1ecb kh\u00f4ng nh\u1ecf h\u01a1n $6$ l\u00e0 $75.$ <br\/> T\u00ecm $x$ t\u1eeb s\u1ed1 c\u00e1c gi\u00e1 tr\u1ecb c\u1ee7a d\u1ea5u hi\u1ec7u. <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> S\u1ed1 c\u00e1c gi\u00e1 tr\u1ecb kh\u00f4ng nh\u1ecf h\u01a1n $6$ l\u00e0: $28+30+y=58+y$ <br\/> M\u00e0 s\u1ed1 c\u00e1c gi\u00e1 tr\u1ecb kh\u00f4ng nh\u1ecf h\u01a1n $6$ l\u00e0 $75$ gi\u00e1 tr\u1ecb n\u00ean: <br\/> $\\begin{align} & 58+y=75 \\\\ & \\Leftrightarrow y=75-58 \\\\ & \\Leftrightarrow y=17 \\\\ \\end{align}$ <br\/> Theo b\u00e0i: <br\/> $\\begin{align} & N=100 \\\\ & \\Leftrightarrow x+15+28+30+17=100 \\\\ & \\Leftrightarrow x+90=100 \\\\ & \\Leftrightarrow x=100-90 \\\\ & \\Leftrightarrow x=10 \\\\ \\end{align}$ <br\/> <span class='basic_pink'>V\u1eady c\u00e1c s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o c\u00e1c \u00f4 tr\u1ed1ng l\u1ea7n l\u01b0\u1ee3t l\u00e0 $10$ v\u00e0 $17.$<\/span><\/span>"}]}],"id_ques":1018},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"\u0110\u1ec1 chung cho hai c\u00e2u","temp":"fill_the_blank","correct":[[["2"],["12"],["7"],["49"],["3"],["24"],["6"],["54"],["5"],["50"],["8"],["88"],["31"],["277"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":" <span class='basic_left'> Cho bi\u1ec3u \u0111\u1ed3 sau v\u1edbi tr\u1ee5c ho\u00e0nh th\u1ec3 hi\u1ec7n <b> gi\u00e1 tr\u1ecb $(x)$<\/b>, tr\u1ee5c tung th\u1ec3 hi\u1ec7n <b> t\u1ea7n s\u1ed1 $(n)$ <\/b> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop7/toan/daiso/bai23/lv2/img\/D7B23TB1_6.png' \/><\/center> <b>C\u00e2u 1.<\/b> T\u1eeb bi\u1ec3u \u0111\u1ed3 tr\u00ean h\u00e3y \u0111i\u1ec1n v\u00e0o c\u00e1c \u00f4 tr\u1ed1ng \u0111\u1ec3 ho\u00e0n th\u00e0nh b\u1ea3ng sau: <br\/> <table><tr><th>Gi\u00e1 tr\u1ecb $(x)$<\/th><th>T\u1ea7n s\u1ed1 $(n)$<\/th><th>C\u00e1c t\u00edch $(x.n)$<\/th><\/tr><tr><td>6<\/td><td>_input_<\/td><td>_input_<\/td><\/tr><tr><td>7<\/td><td>_input_<\/td><td>_input_<\/td><\/tr><tr><td>8<\/td><td>_input_<\/td><td>_input_<\/td><\/tr><tr><td>9<\/td><td>_input_<\/td><td>_input_<\/td><\/tr><tr><td>10<\/td><td>_input_<\/td><td>_input_<\/td><\/tr><tr><td>11<\/td><td>_input_<\/td><td>_input_<\/td><\/tr><tr><td><\/td><td>$N=$ _input_ <\/td><td>T\u1ed5ng: _input_<\/td><\/tr><\/table> <\/span>","explain":" <span class='basic_left'> Ta c\u00f3 b\u1ea3ng ho\u00e0n ch\u1ec9nh nh\u01b0 sau: <br\/> <table><tr><th>Gi\u00e1 tr\u1ecb $(x)$<\/th><th>T\u1ea7n s\u1ed1 $(n)$<\/th><th>C\u00e1c t\u00edch $(x.n)$<\/th><\/tr><tr><td>6<\/td><td>2<\/td><td>12<\/td><\/tr><tr><td>7<\/td><td>7<\/td><td>49<\/td><\/tr><tr><td>8<\/td><td>3<\/td><td>24<\/td><\/tr><tr><td>9<\/td><td>6<\/td><td>54<\/td><\/tr><tr><td>10<\/td><td>5<\/td><td>50<\/td><\/tr><tr><td>11<\/td><td>8<\/td><td>88<\/td><\/tr><tr><td><\/td><td>$N=31$<\/td><td>T\u1ed5ng: $277$<\/td><\/tr><\/table> <br\/> <\/span>"}]}],"id_ques":1019},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"\u0110\u1ec1 chung cho hai c\u00e2u","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" <span class='basic_left'>Cho bi\u1ec3u \u0111\u1ed3 sau v\u1edbi tr\u1ee5c ho\u00e0nh th\u1ec3 hi\u1ec7n <b> gi\u00e1 tr\u1ecb $(x)$<\/b>, tr\u1ee5c tung th\u1ec3 hi\u1ec7n <b> t\u1ea7n s\u1ed1 $(n)$ <\/b> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop7/toan/daiso/bai23/lv2/img\/D7B23TB1_6.png' \/><\/center> <b>C\u00e2u 2.<\/b> S\u1ed1 trung b\u00ecnh c\u1ed9ng c\u1ee7a d\u1ea5u hi\u1ec7u (l\u00e0m tr\u00f2n \u0111\u1ebfn ch\u1eef s\u1ed1 th\u1eadp ph\u00e2n th\u1ee9 hai) l\u00e0 $ 8,94 $<\/span>","select":["\u0110\u00fang","Sai"],"explain":"<span class='basic_left'> Theo c\u00e2u 1, ta c\u00f3 b\u1ea3ng: <br\/> <table><tr><th>Gi\u00e1 tr\u1ecb $(x)$<\/th><th>T\u1ea7n s\u1ed1 $(n)$<\/th><th>C\u00e1c t\u00edch $(x.n)$<\/th><\/tr><tr><td>6<\/td><td>2<\/td><td>12<\/td><\/tr><tr><td>7<\/td><td>7<\/td><td>49<\/td><\/tr><tr><td>8<\/td><td>3<\/td><td>24<\/td><\/tr><tr><td>9<\/td><td>6<\/td><td>54<\/td><\/tr><tr><td>10<\/td><td>5<\/td><td>50<\/td><\/tr><tr><td>11<\/td><td>8<\/td><td>88<\/td><\/tr><tr><td><\/td><td>$N=31$<\/td><td>T\u1ed5ng: $277$<\/td><\/tr><\/table> <br\/> S\u1ed1 trung b\u00ecnh c\u1ed9ng c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0:<br\/> $\\overline{X}=\\dfrac{277}{31} \\approx 8,94$ <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 \u0110\u00fang.<\/span><\/span>","column":2}]}],"id_ques":1020},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["5"],["2014"],["2011"],["58"]]],"list":[{"point":5,"width":60,"content":"","type_input":"","ques":" <span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop7/toan/daiso/bai23/lv2/img\/D7B23TB1_7.png' \/><\/center> Ng\u01b0\u1eddi ta th\u1ed1ng k\u00ea s\u1ea3n l\u01b0\u1ee3ng l\u00faa c\u1ee7a m\u1ed9t \u0111\u1ecba ph\u01b0\u01a1ng trong c\u00e1c n\u0103m t\u00ednh theo t\u1ea5n r\u1ed3i bi\u1ec3u di\u1ec5n th\u00e0nh bi\u1ec3u \u0111\u1ed3 \u1edf tr\u00ean. <br\/> \u0110i\u1ec1n v\u00e0o c\u00e1c \u00f4 tr\u1ed1ng sau \u0111\u1ec3 \u0111\u01b0\u1ee3c c\u00e1c kh\u1eb3ng \u0111\u1ecbnh \u0111\u00fang: <br\/> - S\u1ed1 n\u0103m \u0111\u01b0\u1ee3c th\u1ed1ng k\u00ea l\u00e0 _input_ <br\/> - N\u0103m _input_ c\u00f3 s\u1ea3n l\u01b0\u1ee3ng l\u00faa nhi\u1ec1u nh\u1ea5t <br\/> - N\u0103m _input_ c\u00f3 s\u1ea3n l\u01b0\u1ee3ng l\u00faa \u00edt nh\u1ea5t <br\/> - Ch\u00eanh l\u1ec7ch gi\u1eefa s\u1ea3n l\u01b0\u1ee3ng l\u00faa nhi\u1ec1u nh\u1ea5t v\u00e0 \u00edt nh\u1ea5t l\u00e0 _input_ (t\u1ea5n) <\/span>","explain":" <span class='basic_left'> Theo bi\u1ec3u \u0111\u1ed3 \u0111\u00e3 cho, ta c\u00f3: <br\/> - S\u1ed1 n\u0103m \u0111\u01b0\u1ee3c th\u1ed1ng k\u00ea l\u00e0 $5.$ G\u1ed3m c\u00e1c n\u0103m: $2007;2008;2010;2011;2014$ <br\/> - N\u0103m $2014$ c\u00f3 s\u1ea3n l\u01b0\u1ee3ng l\u00faa nhi\u1ec1u nh\u1ea5t <br\/> - N\u0103m $2011$ c\u00f3 s\u1ea3n l\u01b0\u1ee3ng l\u00faa \u00edt nh\u1ea5t <br\/> - Ch\u00eanh l\u1ec7ch gi\u1eefa s\u1ea3n l\u01b0\u1ee3ng l\u00faa nhi\u1ec1u nh\u1ea5t v\u00e0 \u00edt nh\u1ea5t l\u00e0: $159-101=58$ (t\u1ea5n) <br\/> <span class='basic_pink'>V\u1eady c\u00e1c s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o c\u00e1c \u00f4 tr\u1ed1ng l\u1ea7n l\u01b0\u1ee3t l\u00e0 $5;2014;2011;58$<\/span> <\/span>"}]}],"id_ques":1021},{"time":5,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00fang ho\u1eb7c sai","title_trans":"","temp":"true_false","correct":[["f","t","f","f"]],"list":[{"point":10,"image":"","col_name":["Kh\u1eb3ng \u0111\u1ecbnh","\u0110\u00fang","Sai"],"arr_ques":["M\u1ed1t l\u00e0 t\u1ea7n s\u1ed1 l\u1edbn nh\u1ea5t trong b\u1ea3ng. ","S\u1ed1 trung b\u00ecnh c\u1ed9ng th\u01b0\u1eddng \u0111\u01b0\u1ee3c d\u00f9ng l\u00e0m \u201c\u0111\u1ea1i di\u1ec7n\u201d cho d\u1ea5u hi\u1ec7u, \u0111\u1eb7c bi\u1ec7t l\u00e0 khi mu\u1ed1n so s\u00e1nh c\u00e1c d\u1ea5u hi\u1ec7u c\u00f9ng lo\u1ea1i.","S\u1ed1 c\u00e1c gi\u00e1 tr\u1ecb kh\u00e1c nhau \u0111\u01b0\u1ee3c k\u00ed hi\u1ec7u l\u00e0 $N.$","S\u1ed1 c\u00e1c gi\u00e1 tr\u1ecb b\u1eb1ng t\u1ed5ng c\u00e1c gi\u00e1 tr\u1ecb c\u1ee7a d\u1ea5u hi\u1ec7u \u0111\u00f3."],"hint":"","explain":["Sai, v\u00ec: M\u1ed1t l\u00e0 gi\u00e1 tr\u1ecb c\u00f3 t\u1ea7n s\u1ed1 l\u1edbn nh\u1ea5t ","<br\/> \u0110\u00fang","<br\/> Sai, v\u00ec: $N$ l\u00e0 k\u00ed hi\u1ec7u c\u1ee7a s\u1ed1 c\u00e1c gi\u00e1 tr\u1ecb c\u1ee7a d\u1ea5u hi\u1ec7u","<br\/>Sai, v\u00ec: S\u1ed1 c\u00e1c gi\u00e1 tr\u1ecb $(N)$ b\u1eb1ng t\u1ed5ng t\u1ea7n s\u1ed1 c\u1ee7a c\u00e1c gi\u00e1 tr\u1ecb"]}]}],"id_ques":1022},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"\u0110\u1ec1 chung cho hai c\u00e2u","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" <span class='basic_left'>Cho b\u1ea3ng \u201ct\u1ea7n s\u1ed1\u201d sau: <br\/> <table><tr><th>Gi\u00e1 tr\u1ecb $(x)$<\/th><th>15<\/th><th>18<\/th><th>22<\/th><th>24<\/th><th>x<\/th><th><\/th><\/tr><tr><td>T\u1ea7n s\u1ed1 $(n)$<\/td><td>3<\/td><td>y<\/td><td>5<\/td><td>7<\/td><td>6<\/td><td>$N=25$<\/td><\/tr><\/table> <br\/> <b> C\u00e2u 1. <\/b> T\u00ecm $y,$ t\u1eeb \u0111\u00f3 t\u00ecm m\u1ed1t c\u1ee7a d\u1ea5u hi\u1ec7u.<\/span>","select":["A. $y= 4; M_o=24$","B. $y=4; M_o=7$","C. $y=8;M_o=18$","D. $y=8;M_o=8$"],"explain":"<span class='basic_left'>Theo b\u00e0i, ta c\u00f3: <br\/> $\\begin{align} & N=25 \\\\ & \\Leftrightarrow 3+y+5+7+6=25 \\\\ & \\Leftrightarrow 21+y=25 \\\\ & \\Leftrightarrow y=25-21=4 \\\\ \\end{align}$ <br\/> V\u1edbi $y = 4$ th\u00ec gi\u00e1 tr\u1ecb $24$ c\u00f3 t\u1ea7n s\u1ed1 l\u1edbn nh\u1ea5t l\u00e0 $7.$ <br\/> Do \u0111\u00f3, m\u1ed1t c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0 $24.$ <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 A.<\/span><\/span>","column":2}]}],"id_ques":1023},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"\u0110\u1ec1 chung cho hai c\u00e2u","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":" <span class='basic_left'>Cho b\u1ea3ng \u201ct\u1ea7n s\u1ed1\u201d sau: <br\/> <table><tr><th>Gi\u00e1 tr\u1ecb $(x)$<\/th><th>15<\/th><th>18<\/th><th>22<\/th><th>24<\/th><th>$x$<\/th><th><\/th><\/tr><tr><td>T\u1ea7n s\u1ed1 $(n)$<\/td><td>3<\/td><td>$y$<\/td><td>5<\/td><td>7<\/td><td>6<\/td><td>$N=25$<\/td><\/tr><\/table> <br\/> <b> C\u00e2u 2. <\/b> T\u00ecm $x,$ bi\u1ebft s\u1ed1 trung b\u00ecnh c\u1ed9ng c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0 $23.$<\/span>","select":["A. $x=26$","B. $x=28$","C. $x=30$","D. $x=31$"],"explain":"<span class='basic_left'> Ta c\u00f3: $y=4$ (theo c\u00e2u 1) <br\/> Theo b\u00e0i, s\u1ed1 trung b\u00ecnh c\u1ed9ng c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0 $23$ n\u00ean: <br\/> $\\begin{align} & \\overline{X}=23 \\\\ & \\Leftrightarrow \\dfrac{15.3+18.4+22.5+24.7+x.6}{25}=23 \\\\ & \\Leftrightarrow \\dfrac{395+6x}{25}=23 \\\\ & \\Leftrightarrow 395+6x=575 \\\\ & \\Leftrightarrow 6x=180 \\\\ & \\Leftrightarrow x=30 \\\\ \\end{align}$ <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 C.<\/span><\/span>","column":2}]}],"id_ques":1024},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":" <span class='basic_left'>\u1ede v\u00f9ng x\u00edch \u0111\u1ea1o c\u1ee7a M\u1eb7t Tr\u0103ng, nhi\u1ec7t \u0111\u1ed9 l\u00fac gi\u1eefa tr\u01b0a l\u00e0 $120^o$, c\u00f2n nhi\u1ec7t \u0111\u1ed9 l\u00fac n\u1eeda \u0111\u00eam l\u00e0 $-160^o.$ <br\/> Kh\u1eb3ng \u0111\u1ecbnh sau \u0111\u00e2y \u0110\u00fang hay Sai? <br\/> Nhi\u1ec7t \u0111\u1ed9 trung b\u00ecnh \u1edf v\u00f9ng x\u00edch \u0111\u1ea1o c\u1ee7a M\u1eb7t Tr\u0103ng t\u00ednh \u0111\u01b0\u1ee3c s\u1ebd l\u00e0 \u201c\u0111\u1ea1i di\u1ec7n\u201d cho nhi\u1ec7t \u0111\u1ed9 trung b\u00ecnh \u1edf v\u00f9ng x\u00edch \u0111\u1ea1o c\u1ee7a M\u1eb7t Tr\u0103ng. <\/span>","select":["\u0110\u00fang","Sai"],"explain":"<span class='basic_left'>V\u00ec c\u00e1c nhi\u1ec7t \u0111\u1ed9 \u0111\u00e3 cho l\u00e0 $120^o$ v\u00e0 $-160^o$ ch\u00eanh l\u1ec7ch nhau qu\u00e1 nhi\u1ec1u n\u00ean s\u1ed1 trung b\u00ecnh c\u1ed9ng c\u1ee7a ch\u00fang kh\u00f4ng \u201c\u0111\u1ea1i di\u1ec7n\u201d \u0111\u01b0\u1ee3c cho d\u1ea5u hi\u1ec7u. <br\/> T\u1ee9c l\u00e0: Nhi\u1ec7t \u0111\u1ed9 trung b\u00ecnh \u1edf v\u00f9ng x\u00edch \u0111\u1ea1o c\u1ee7a M\u1eb7t Tr\u0103ng t\u00ednh \u0111\u01b0\u1ee3c kh\u00f4ng \u201c\u0111\u1ea1i di\u1ec7n\u201d cho nhi\u1ec7t \u0111\u1ed9 trung b\u00ecnh \u1edf v\u00f9ng x\u00edch \u0111\u1ea1o c\u1ee7a M\u1eb7t Tr\u0103ng. <br\/> Do \u0111\u00f3, kh\u1eb3ng \u0111\u1ecbnh tr\u00ean l\u00e0 sai. <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 Sai.<\/span> <br\/> <b>Sai l\u1ea7m c\u1ea7n tr\u00e1nh: <\/b> <i> Khi c\u00e1c gi\u00e1 tr\u1ecb c\u1ee7a d\u1ea5u hi\u1ec7u ch\u00eanh l\u1ec7ch nhau qu\u00e1 nhi\u1ec1u th\u00ec s\u1ed1 trung b\u00ecnh c\u1ed9ng c\u1ee7a ch\u00fang kh\u00f4ng \u201c\u0111\u1ea1i di\u1ec7n\u201d \u0111\u01b0\u1ee3c cho d\u1ea5u hi\u1ec7u. <\/i><\/span>","column":2}]}],"id_ques":1025},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"\u0110\u1ec1 chung cho ba c\u00e2u","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":" <span class='basic_left'>\u0110\u1ec3 t\u00ecm hi\u1ec3u v\u1ec1 n\u0103ng su\u1ea5t l\u00faa v\u1ee5 m\u00f9a c\u1ee7a m\u1ed9t x\u00e3, ng\u01b0\u1eddi ta ch\u1ecdn ra $N$ th\u1eeda ru\u1ed9ng \u0111\u1ec3 g\u1eb7t th\u1eed. K\u1ebft qu\u1ea3 nh\u01b0 sau: <br\/> - C\u00f3 $4$ th\u1eeda ru\u1ed9ng \u0111\u1ea1t n\u0103ng su\u1ea5t $32$ t\u1ea1\/ha <br\/> - C\u00f3 $6$ th\u1eeda ru\u1ed9ng \u0111\u1ea1t n\u0103ng su\u1ea5t $34$ t\u1ea1\/ha <br\/> - C\u00f3 $7$ th\u1eeda ru\u1ed9ng \u0111\u1ea1t n\u0103ng su\u1ea5t $36$ t\u1ea1\/ha <br\/> - C\u00f3 $10$ th\u1eeda ru\u1ed9ng \u0111\u1ea1t n\u0103ng su\u1ea5t $37$ t\u1ea1\/ha <br\/> - C\u00f3 $8$ th\u1eeda ru\u1ed9ng \u0111\u1ea1t n\u0103ng su\u1ea5t $40$ t\u1ea1\/ha <br\/> - C\u00f3 $5$ th\u1eeda ru\u1ed9ng \u0111\u1ea1t n\u0103ng su\u1ea5t $42$ t\u1ea1\/ha <br\/> <b>C\u00e2u 1.<\/b> T\u00ednh $N.$ <\/span>","select":["A. $N=30$","B. $N=40$","C. $N=50$","D. $N=60$"],"explain":"<span class='basic_left'>$N$ l\u00e0 t\u1ed5ng s\u1ed1 th\u1eeda ru\u1ed9ng \u0111\u01b0\u1ee3c g\u1eb7t th\u1eed, ta c\u00f3: <br\/> $N=4+6+7+10+8+5=40$ <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 B.<\/span><\/span>","column":4}]}],"id_ques":1026},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"\u0110\u1ec1 chung cho ba c\u00e2u","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":" <span class='basic_left'>\u0110\u1ec3 t\u00ecm hi\u1ec3u v\u1ec1 n\u0103ng su\u1ea5t l\u00faa v\u1ee5 m\u00f9a c\u1ee7a m\u1ed9t x\u00e3, ng\u01b0\u1eddi ta ch\u1ecdn ra $N$ th\u1eeda ru\u1ed9ng \u0111\u1ec3 g\u1eb7t th\u1eed. K\u1ebft qu\u1ea3 nh\u01b0 sau: <br\/> - C\u00f3 $4$ th\u1eeda ru\u1ed9ng \u0111\u1ea1t n\u0103ng su\u1ea5t $32$ t\u1ea1\/ha <br\/> - C\u00f3 $6$ th\u1eeda ru\u1ed9ng \u0111\u1ea1t n\u0103ng su\u1ea5t $34$ t\u1ea1\/ha <br\/> - C\u00f3 $7$ th\u1eeda ru\u1ed9ng \u0111\u1ea1t n\u0103ng su\u1ea5t $36$ t\u1ea1\/ha <br\/> - C\u00f3 $10$ th\u1eeda ru\u1ed9ng \u0111\u1ea1t n\u0103ng su\u1ea5t $37$ t\u1ea1\/ha <br\/> - C\u00f3 $8$ th\u1eeda ru\u1ed9ng \u0111\u1ea1t n\u0103ng su\u1ea5t $40$ t\u1ea1\/ha <br\/> - C\u00f3 $5$ th\u1eeda ru\u1ed9ng \u0111\u1ea1t n\u0103ng su\u1ea5t $42$ t\u1ea1\/ha <br\/> <b>C\u00e2u 2.<\/b> M\u1ed1t c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0: <\/span>","select":["A. $10$","B. $42$","C. $37$","D. $32$"],"explain":"<span class='basic_left'>Ta th\u1ea5y c\u00f3 $10$ th\u1eeda ru\u1ed9ng \u0111\u1ea1t n\u0103ng su\u1ea5t $37$ t\u1ea1\/ha. T\u1ee9c l\u00e0 gi\u00e1 tr\u1ecb $37$ c\u00f3 t\u1ea7n s\u1ed1 l\u1edbn nh\u1ea5t l\u00e0 $10.$ <br\/> Do \u0111\u00f3, m\u1ed1t c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0 $37.$ <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 C.<\/span><\/span>","column":4}]}],"id_ques":1027},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"\u0110\u1ec1 chung cho ba c\u00e2u","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" <span class='basic_left'>\u0110\u1ec3 t\u00ecm hi\u1ec3u v\u1ec1 n\u0103ng su\u1ea5t l\u00faa v\u1ee5 m\u00f9a c\u1ee7a m\u1ed9t x\u00e3, ng\u01b0\u1eddi ta ch\u1ecdn ra $N$ th\u1eeda ru\u1ed9ng \u0111\u1ec3 g\u1eb7t th\u1eed. K\u1ebft qu\u1ea3 nh\u01b0 sau: <br\/> - C\u00f3 $4$ th\u1eeda ru\u1ed9ng \u0111\u1ea1t n\u0103ng su\u1ea5t $32$ t\u1ea1\/ha <br\/> - C\u00f3 $6$ th\u1eeda ru\u1ed9ng \u0111\u1ea1t n\u0103ng su\u1ea5t $34$ t\u1ea1\/ha <br\/> - C\u00f3 $7$ th\u1eeda ru\u1ed9ng \u0111\u1ea1t n\u0103ng su\u1ea5t $36$ t\u1ea1\/ha <br\/> - C\u00f3 $10$ th\u1eeda ru\u1ed9ng \u0111\u1ea1t n\u0103ng su\u1ea5t $37$ t\u1ea1\/ha <br\/> - C\u00f3 $8$ th\u1eeda ru\u1ed9ng \u0111\u1ea1t n\u0103ng su\u1ea5t $40$ t\u1ea1\/ha <br\/> - C\u00f3 $5$ th\u1eeda ru\u1ed9ng \u0111\u1ea1t n\u0103ng su\u1ea5t $42$ t\u1ea1\/ha <br\/> <b>C\u00e2u 3.<\/b> Trung b\u00ecnh m\u1ed7i th\u1eeda ru\u1ed9ng c\u00f3 n\u0103ng su\u1ea5t l\u00e0: <\/span>","select":["A. $37,1$ t\u1ea1\/ha ","B. $38,2$ t\u1ea1\/ha ","C. $39$ t\u1ea1\/ha ","D. $39,5$ t\u1ea1\/ha"],"explain":"<span class='basic_left'>Ta c\u00f3 b\u1ea3ng sau: <br\/> <table><tr><th>Gi\u00e1 tr\u1ecb $(x)$<\/th><th>32<\/th><th>34<\/th><th>36<\/th><th>37<\/th><th>40<\/th><th>42<\/th><th><\/th><\/tr><tr><td>T\u1ea7n s\u1ed1 $(n)$<\/td><td>4<\/td><td>6<\/td><td>7<\/td><td>10<\/td><td>8<\/td><td>5<\/td><td>$N=40$<\/td><\/tr><tr><td>C\u00e1c t\u00edch $(x.n)$<\/td><td>128<\/td><td>204<\/td><td>252<\/td><td>370<\/td><td>320<\/td><td>210<\/td><td>T\u1ed5ng: $1484$<\/td><\/tr><\/table> <br\/> Trung b\u00ecnh m\u1ed7i th\u1eeda ru\u1ed9ng c\u00f3 n\u0103ng su\u1ea5t l\u00e0: <br\/> $\\overline{X}=\\dfrac{1484}{40}=37,1$ (t\u1ea1\/ha) <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 A.<\/span><\/span>","column":2}]}],"id_ques":1028},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"\u0110\u1ec1 chung cho hai c\u00e2u","temp":"fill_the_blank","correct":[[["0,57","0.57"]]],"list":[{"point":5,"width":60,"content":"","type_input":"","ques":" <span class='basic_left'> Th\u1eddi gian ch\u1ea1y $50m$ c\u1ee7a $20$ h\u1ecdc sinh nam v\u00e0 $20$ h\u1ecdc sinh n\u1eef \u0111\u01b0\u1ee3c th\u1ea7y gi\u00e1o th\u1ec3 d\u1ee5c ghi l\u1ea1i trong b\u1ea3ng d\u01b0\u1edbi \u0111\u00e2y: <br\/> - \u0110\u1ed1i v\u1edbi h\u1ecdc sinh nam <br\/> <table><tr><th>Th\u1eddi gian ch\u1ea1y (gi\u00e2y)<\/th><th>8,3<\/th><th>8,4<\/th><th>8,5<\/th><th>8,7<\/th><th>8,8<\/th><th><\/th><\/tr><tr><td>T\u1ea7n s\u1ed1 $(n)$<\/td><td>2<\/td><td>3<\/td><td>9<\/td><td>5<\/td><td>1<\/td><td>$N=20$<\/td><\/tr><\/table> <br\/> - \u0110\u1ed1i v\u1edbi h\u1ecdc sinh n\u1eef <br\/> <table><tr><th>Th\u1eddi gian ch\u1ea1y (gi\u00e2y)<\/th><th>8,7<\/th><th>9,0<\/th><th>9,2<\/th><th>9,3<\/th><th><\/th><\/tr><tr><td>T\u1ea7n s\u1ed1 $(n)$<\/td><td>3<\/td><td>5<\/td><td>7<\/td><td>5<\/td><td>$N=20$<\/td><\/tr><\/table> <br\/> <b>C\u00e2u 1.<\/b> T\u00ednh hi\u1ec7u th\u1eddi gian th\u1eddi gian ch\u1ea1y trung b\u00ecnh c\u1ee7a $20$ h\u1ecdc sinh n\u1eef ($\\overline{{{X}_{2}}}$ ) v\u1edbi th\u1eddi gian ch\u1ea1y trung b\u00ecnh c\u1ee7a $20$ h\u1ecdc sinh nam ($\\overline{{{X}_{1}}}$ ) <br\/> <b>\u0110\u00e1p \u00e1n:<\/b> $\\overline{{{X}_{2}}}-\\overline{{{X}_{1}}}$ = _input_ <br\/> (l\u00e0m tr\u00f2n \u0111\u1ebfn ch\u1eef s\u1ed1 th\u1eadp ph\u00e2n th\u1ee9 hai)<\/span>","explain":"<span class='basic_left'> S\u1ed1 trung b\u00ecnh c\u1ed9ng th\u1eddi gian ch\u1ea1y c\u1ee7a m\u1ed7i lo\u1ea1i h\u1ecdc sinh: <br\/> - \u0110\u1ed1i v\u1edbi h\u1ecdc sinh nam <br\/> $\\begin{align} &\\overline{{{X}_{1}}}=\\dfrac{8,3.2+8,4.3+8,5.9+8,7.5+8,8.1}{20} \\\\ & \\,\\,\\,\\,\\,\\,\\,\\,=\\frac{170,6}{20} \\\\ & \\,\\,\\,\\,\\,\\,\\,\\,=8,53\\,\\,\\,\\left( \\text{gi\u00e2y} \\right) \\\\ \\end{align}$ <br\/> - \u0110\u1ed1i v\u1edbi h\u1ecdc sinh n\u1eef <br\/> $\\begin{align} & \\overline{{{X}_{2}}}=\\dfrac{8,7.3+9,0.5+9,2.7+9,3.5}{20} \\\\ & \\,\\,\\,\\,\\,\\,\\,\\,=\\dfrac{182,0}{20} \\\\ & \\,\\,\\,\\,\\,\\,\\,\\,=9,1\\,\\,\\,\\left( \\text{gi\u00e2y} \\right) \\\\ \\end{align}$ <br\/> Suy ra $\\overline{{{X}_{2}}}-\\overline{{{X}_{1}}}=9,1-8,53=0,57$ <br\/> <span class='basic_pink'> V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $0,57$.<\/span><\/span>"}]}],"id_ques":1029},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"\u0110\u1ec1 chung cho hai c\u00e2u","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" <span class='basic_left'> Th\u1eddi gian ch\u1ea1y $50m$ c\u1ee7a $20$ h\u1ecdc sinh nam v\u00e0 $20$ h\u1ecdc sinh n\u1eef \u0111\u01b0\u1ee3c th\u1ea7y gi\u00e1o th\u1ec3 d\u1ee5c ghi l\u1ea1i trong b\u1ea3ng d\u01b0\u1edbi \u0111\u00e2y: <br\/> - \u0110\u1ed1i v\u1edbi h\u1ecdc sinh nam <br\/> <table><tr><th>Th\u1eddi gian ch\u1ea1y (gi\u00e2y)<\/th><th>8,3<\/th><th>8,4<\/th><th>8,5<\/th><th>8,7<\/th><th>8,7<\/th><th><\/th><\/tr><tr><td>T\u1ea7n s\u1ed1 $(n)$<\/td><td>2<\/td><td>3<\/td><td>9<\/td><td>5<\/td><td>1<\/td><td>$N=20$<\/td><\/tr><\/table> <br\/> - \u0110\u1ed1i v\u1edbi h\u1ecdc sinh n\u1eef <br\/> <table><tr><th>Th\u1eddi gian ch\u1ea1y (gi\u00e2y)<\/th><th>8,7<\/th><th>9,0<\/th><th>9,2<\/th><th>9,3<\/th><th><\/th><\/tr><tr><td>T\u1ea7n s\u1ed1 $(n)$<\/td><td>3<\/td><td>5<\/td><td>7<\/td><td>5<\/td><td>$N=20$<\/td><\/tr><\/table> <br\/> <b>C\u00e2u 2.<\/b> Nh\u1eadn x\u00e9t sau \u0110\u00fang hay Sai? <br\/> - Th\u1eddi gian ch\u1ea1y c\u1ee7a c\u00e1c h\u1ecdc sinh nam ch\u1ee7 y\u1ebfu trong kho\u1ea3ng t\u1eeb $8,5$ \u0111\u1ebfn $8,7$ gi\u00e2y v\u00e0 $M_o=8,5$ <br\/> - Th\u1eddi gian ch\u1ea1y c\u1ee7a c\u00e1c h\u1ecdc sinh n\u1eef ch\u1ee7 y\u1ebfu trong kho\u1ea3ng t\u1eeb $9,0 $ \u0111\u1ebfn $9,3$ gi\u00e2y v\u00e0 $M_o=9,2$ <\/span>","select":["\u0110\u00fang ","Sai"],"explain":"<span class='basic_left'>Nh\u00ecn v\u00e0o b\u1ea3ng s\u1ed1 li\u1ec7u \u0111\u00e3 cho ban \u0111\u1ea7u ta th\u1ea5y: <br\/> - \u0110\u1ed1i v\u1edbi h\u1ecdc sinh nam: c\u00e1c gi\u00e1 tr\u1ecb $8,5$ v\u00e0 $8,7$ c\u00f3 t\u1ea7n s\u1ed1 l\u1edbn h\u01a1n h\u1eb3n so v\u1edbi c\u00e1c gi\u00e1 tr\u1ecb c\u00f2n l\u1ea1i. Gi\u00e1 tr\u1ecb $8,5$ c\u00f3 t\u1ea7n s\u1ed1 l\u1edbn nh\u1ea5t l\u00e0 $8$ n\u00ean $M_o=8,5$. Do \u0111\u00f3 nh\u1eadn x\u00e9t v\u1ec1 c\u00e1c h\u1ecdc sinh nam l\u00e0 \u0111\u00fang. <br\/> - \u0110\u1ed1i v\u1edbi c\u00e1c h\u1ecdc sinh n\u1eef c\u0169ng t\u01b0\u01a1ng t\u1ef1. <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 \u0110\u00fang.<\/span><\/span>","column":2}]}],"id_ques":1030}],"lesson":{"save":0,"level":2}}