Trong m\u1ed9t cu\u1ed9c thi h\u00e1t, u\u1ef7 vi\u00ean ch\u1ea5m thi th\u01b0\u1eddng tuy\u00ean b\u1ed1 \u0111i\u1ec3m s\u1ed1 9,00, 9,50, 9,55, 9,6, 9,75, 9,90. Nh\u01b0ng khi t\u00ednh \u0111i\u1ec3m b\u00ecnh qu\u00e2n ng\u01b0\u1eddi ta \u0111\u00e3 b\u1ecf c\u00e1c \u0111i\u1ec3m s\u1ed1 qu\u00e1 b\u00e9 v\u00e0 qu\u00e1 l\u1edbn v\u00e0 t\u00ednh \u0111i\u1ec3m b\u00ecnh qu\u00e2n nh\u01b0 sau:<\/p>\n\n\n\n
V\u00ec sao ng\u01b0\u1eddi ta l\u1ea1i b\u1ecf \u0111i c\u00e1c \u0111i\u1ec3m qu\u00e1 cao v\u00e0 qu\u00e1 th\u1ea5p? \u0110\u00f3 l\u00e0 \u0111\u1ec3 lo\u1ea1i b\u1ecf c\u00e1c \u0111i\u1ec3m kh\u00e1c th\u01b0\u1eddng. \u0110i\u1ec3m kh\u00e1c th\u01b0\u1eddng l\u00e0 nh\u1eefng s\u1ed1 qu\u00e1 l\u1edbn ho\u1eb7c qu\u00e1 b\u00e9 so v\u1edbi s\u1ed1 b\u00ecnh qu\u00e2n.<\/p>\n\n\n\n
Th\u00f4ng th\u01b0\u1eddng c\u00e1c \u0111i\u1ec3m kh\u00e1c th\u01b0\u1eddng l\u00e0 do tr\u1ecdng t\u00e0i s\u01a1 \u00fd v\u00e0 c\u00e1c y\u1ebfu t\u1ed1 t\u00e2m l\u00ed ho\u1eb7c qu\u00e1 ph\u1eabn n\u1ed9 ho\u1eb7c qu\u00e1 ph\u1ea5n ch\u1ea5n g\u00e2y n\u00ean. \u0110\u1ec3 gi\u1ea3m b\u1edbt c\u00e1c \u0111i\u1ec3m kh\u00e1c th\u01b0\u1eddng l\u00e0m \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn \u0111\u1ed9 ch\u00ednh x\u00e1c c\u1ee7a k\u1ebft qu\u1ea3 \u0111i\u1ec3m b\u00ecnh qu\u00e2n, vi\u1ec7c lo\u1ea1i b\u1ecf c\u00e1c \u0111i\u1ec3m kh\u00e1c qu\u00e1 cao ho\u1eb7c qu\u00e1 th\u1ea5p l\u00e0 h\u1ee3p l\u00ed.<\/p>\n\n\n\n
\u0110i\u1ec1u n\u00e0y c\u00f3 li\u00ean quan \u0111\u1ebfn kh\u00e1i ni\u1ec7m s\u1ed1 trung v\u1ecb trong to\u00e1n h\u1ecdc.<\/p>\n\n\n\n
Nh\u01b0ng th\u1ebf n\u00e0o l\u00e0 s\u1ed1 trung v\u1ecb? Ta l\u1ea1i th\u1eed xem x\u00e9t v\u00ed d\u1ee5 tr\u00ean kia, c\u1ee9 theo th\u1ee9 t\u1ef1 s\u1eafp x\u1ebfp c\u1ee7a s\u00e1u s\u1ed1 nh\u01b0 tr\u00ean ta l\u1ea5y b\u00ecnh qu\u00e2n c\u1ee7a ba s\u1ed1 ho\u1eb7c b\u1ed1n s\u1ed1 th\u00ec \u0111i\u1ec3m b\u00ecnh qu\u00e2n s\u1ebd l\u00e0 s\u1ed1 trung b\u00ecnh. (9,55 + 9,6)\/2 = 9,575<\/p>\n\n\n\n
N\u1ebfu s\u1ed1 u\u1ef7 vi\u00ean c\u1ee7a h\u1ed9i \u0111\u1ed3ng ch\u1ea5m thi l\u00e0 s\u1ed1 l\u1ebb, n\u1ebfu l\u1ea5y trung b\u00ecnh t\u1eeb n\u0103m s\u1ed1 \u0111\u1ee9ng tr\u01b0\u1edbc, th\u00ec s\u1ed1 trung v\u1ecb s\u1ebd l\u00e0 9,55 t\u1ee9c l\u00e0 \u0111i\u1ec3m s\u1ed1 th\u1ee9 ba. Khi x\u1eed l\u00ed t\u00ecm s\u1ed1 trung v\u1ecb v\u1edbi c\u00e1c con s\u1ed1 \u1edf b\u00ean tr\u00e1i s\u1ed1 trung b\u00ecnh, ch\u1ec9 c\u1ea7n kh\u00f4ng l\u1edbn h\u01a1n s\u1ed1 trung v\u1ecb th\u00ec c\u0169ng kh\u00f4ng l\u00e0m thay \u0111\u1ed5i s\u1ed1 trung v\u1ecb. Khi x\u1eed l\u00ed v\u1edbi c\u00e1c s\u1ed1 \u1edf b\u00ean ph\u1ea3i s\u1ed1 trung v\u1ecb, ch\u1ec9 c\u1ea7n kh\u00f4ng c\u1ea7n nh\u1ecf h\u01a1n s\u1ed1 trung v\u1ecb th\u00ec c\u0169ng kh\u00f4ng l\u00e0m thay \u0111\u1ed5i gi\u00e1 tr\u1ecb s\u1ed1 trung v\u1ecb. T\u1eeb \u0111\u00f3 c\u00f3 th\u1ec3 th\u1ea5y, s\u1ed1 trung v\u1ecb kh\u00f4ng ch\u1ecbu \u1ea3nh h\u01b0\u1edfng c\u1ee7a c\u00e1c s\u1ed1 qu\u00e1 l\u1edbn ho\u1eb7c qu\u00e1 b\u00e9 c\u1ef1c \u0111oan, c\u00f2n \u0111i\u1ec3m b\u00ecnh qu\u00e2n th\u00ec ch\u1ecbu \u1ea3nh h\u01b0\u1edfng c\u1ee7a m\u1ed7i gi\u00e1 tr\u1ecb trong c\u00e1c s\u1ed1. V\u00ec v\u1eady s\u1ed1 trung v\u1ecb c\u00f3 l\u00fac ph\u1ea3n \u1ea3nh m\u1ee9c \u0111\u1ed9 b\u00ecnh qu\u00e2n. V\u00ed d\u1ee5 trong m\u1ed9t l\u1edbp h\u1ecdc c\u00f3 10 b\u1ea1n tham gia m\u1ed9t cu\u1ed9c thi, c\u00f3 hai ng\u01b0\u1eddi b\u1ecb \u0111i\u1ec3m 0. S\u1ed1 \u0111i\u1ec3m c\u1ee7a nh\u00f3m ng\u01b0\u1eddi s\u1eafp x\u1ebfp nh\u01b0 sau: 0, 0, 65, 69, 70, 72, 78, 81, 85, 89.<\/p>\n\n\n\n
\u0110i\u1ec3m b\u00ecnh qu\u00e2n s\u1ebd l\u00e0:<\/p>\n\n\n\n
Nh\u01b0 v\u1eady ngay b\u1ea1n c\u00f3 \u0111i\u1ec3m s\u1ed1 65 \u0111\u00e3 v\u01b0\u1ee3t \u0111i\u1ec3m b\u00ecnh qu\u00e2n nh\u01b0 v\u1eady l\u00e0 c\u00f3 \u0111i\u1ec3m s\u1ed1 tr\u00ean trung b\u00ecnh.<\/p>\n\n\n\n
\u0110\u01b0\u01a1ng nhi\u00ean kh\u00f4ng ph\u1ea3i nh\u01b0 v\u1eady. N\u1ebfu lo\u1ea1i b\u1ecf hai ng\u01b0\u1eddi b\u1ecb h\u1ecfng thi, th\u00ec anh ch\u00e0ng c\u00f3 \u0111i\u1ec3m thi 65 s\u1ebd \u1edf v\u1ecb tr\u00ed cu\u1ed1i b\u1ea3ng. Nh\u01b0 v\u1eady \u0111i\u1ec3m b\u00ecnh qu\u00e2n kh\u00f4ng ph\u1ea3n \u00e1nh \u0111\u00fang m\u1ee9c \u0111\u1ed9 trung b\u00ecnh. Th\u1ebf nh\u01b0ng n\u1ebfu lo\u1ea1i b\u1ecf \u0111i\u1ec3m h\u1ecfng th\u00ec l\u1ea5y \u0111i\u1ec3m b\u00ecnh qu\u00e2n c\u1ee7a t\u00e1m s\u1ed1 c\u00f2n l\u1ea1i li\u1ec7u c\u00f3 \u0111\u01b0\u1ee3c kh\u00f4ng? \u0110\u01b0\u01a1ng nhi\u00ean kh\u00f4ng \u0111\u01b0\u1ee3c. B\u00e2y gi\u1edd ch\u1ec9 l\u1ea5y \u0111i\u1ec3m trung v\u1ecb l\u00e0 th\u00edch h\u1ee3p. \u0110i\u1ec3m trung v\u1ecb l\u00e0 trung b\u00ecnh gi\u1eefa \u0111i\u1ec3m s\u1ed1 th\u1ee9 n\u0103m v\u00e0 \u0111i\u1ec3m s\u1ed1 th\u1ee9 s\u00e1u, t\u1ee9c 70 + 72 \/ 2 = 71.<\/p>\n\n\n\n
S\u1ed1 \u0111i\u1ec3m l\u1edbn h\u01a1n 71 l\u00e0 tr\u00ean trung b\u00ecnh, nh\u1ecf h\u01a1n 71 l\u00e0 d\u01b0\u1edbi trung b\u00ecnh. Nh\u01b0 v\u1eady \u0111i\u1ec3m trung v\u1ecb m\u1edbi ph\u1ea3n \u00e1nh \u0111\u00fang m\u1ee9c trung b\u00ecnh.<\/p>\n\n\n\n
\u0110\u01b0\u01a1ng nhi\u00ean s\u1ed1 trung b\u00ecnh c\u0169ng c\u00f3 \u01b0u \u0111i\u1ec3m ri\u00eang t\u1ee9c l\u00e0 c\u1ea7n ph\u1ea3i ch\u00fa \u00fd \u0111\u1ebfn t\u1ea5t c\u1ea3 c\u00e1c s\u1ed1. Vi\u1ec7c lo\u1ea1i b\u1ecf c\u00e1c \u0111i\u1ec3m qu\u00e1 l\u1edbn v\u00e0 qu\u00e1 b\u00e9 l\u00e0 \u0111\u00e3 k\u1ebft h\u1ee3p \u0111\u01b0\u1ee3c \u01b0u \u0111i\u1ec3m c\u1ee7a hai ph\u01b0\u01a1ng ph\u00e1p: v\u1eeba lo\u1ea1i b\u1ecf gi\u00e1 tr\u1ecb d\u1ecb th\u01b0\u1eddng v\u1eeba ph\u00e1t huy \u0111\u01b0\u1ee3c t\u00e1c d\u1ee5ng c\u1ee7a phe \u0111a s\u1ed1 trong h\u1ed9i \u0111\u1ed3ng ch\u1ea5m thi n\u00ean \u0111\u00f3 l\u00e0 ph\u01b0\u01a1ng ph\u00e1p h\u1ee3p l\u00ed.<\/p>\n\n\n\n
T\u1eeb kho\u00e1: S\u1ed1 b\u00ecnh qu\u00e2n; \u0110i\u1ec3m trung v\u1ecb.<\/p>\n\n\n\n
<\/p>\n\n\n\n\n\n\n","protected":false},"excerpt":{"rendered":"
Trong m\u1ed9t cu\u1ed9c thi h\u00e1t, u\u1ef7 vi\u00ean ch\u1ea5m thi th\u01b0\u1eddng tuy\u00ean b\u1ed1 \u0111i\u1ec3m s\u1ed1 9,00, 9,50, 9,55, 9,6, 9,75, 9,90. Nh\u01b0ng khi t\u00ednh \u0111i\u1ec3m b\u00ecnh qu\u00e2n ng\u01b0\u1eddi ta \u0111\u00e3 b\u1ecf c\u00e1c \u0111i\u1ec3m s\u1ed1 qu\u00e1 b\u00e9 v\u00e0 qu\u00e1 l\u1edbn v\u00e0 t\u00ednh \u0111i\u1ec3m b\u00ecnh qu\u00e2n nh\u01b0 sau: V\u00ec sao ng\u01b0\u1eddi ta l\u1ea1i b\u1ecf \u0111i c\u00e1c \u0111i\u1ec3m qu\u00e1 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_disable_autopaging":false},"categories":[15,9],"tags":[],"class_list":["post-7599","post","type-post","status-publish","format-standard","hentry","category-hoi-dap-khoa-hoc","category-toan-hoc"],"_links":{"self":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/7599","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/comments?post=7599"}],"version-history":[{"count":0,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/7599\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/media?parent=7599"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/categories?post=7599"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/tags?post=7599"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}