{"id":620587,"date":"2026-11-09T09:17:34","date_gmt":"2026-11-09T02:17:34","guid":{"rendered":"https:\/\/hoanghamobile.com\/tin-tuc\/?p=620587"},"modified":"2026-11-09T09:18:03","modified_gmt":"2026-11-09T02:18:03","slug":"phuong-sai","status":"publish","type":"post","link":"https:\/\/hoanghamobile.com\/tin-tuc\/phuong-sai\/","title":{"rendered":"Ph\u01b0\u01a1ng sai l\u00e0 g\u00ec? C\u00f4ng th\u1ee9c, c\u00e1ch t\u00ednh v\u00e0 v\u00ed d\u1ee5 c\u00f3 l\u1eddi gi\u1ea3i"},"content":{"rendered":"<p>Ph\u01b0\u01a1ng sai l\u00e0 s\u1ed1 \u0111o m\u1ee9c \u0111\u1ed9 ph\u00e2n t\u00e1n c\u1ee7a d\u1eef li\u1ec7u quanh gi\u00e1 tr\u1ecb trung b\u00ecnh, b\u1eb1ng trung b\u00ecnh c\u1ed9ng b\u00ecnh ph\u01b0\u01a1ng c\u00e1c \u0111\u1ed9 l\u1ec7ch: s\u00b2 = [(x\u2081 \u2212 x\u0304)\u00b2 + (x\u2082 \u2212 x\u0304)\u00b2 + \u2026 + (x\u2099 \u2212 x\u0304)\u00b2] \/ n. Ph\u01b0\u01a1ng sai c\u00e0ng l\u1edbn, d\u1eef li\u1ec7u c\u00e0ng ph\u00e2n t\u00e1n; c\u0103n b\u1eadc hai c\u1ee7a ph\u01b0\u01a1ng sai l\u00e0 \u0111\u1ed9 l\u1ec7ch chu\u1ea9n s, c\u00f3 c\u00f9ng \u0111\u01a1n v\u1ecb v\u1edbi d\u1eef li\u1ec7u. B\u00e0i vi\u1ebft tr\u00ecnh b\u00e0y c\u00f4ng th\u1ee9c cho m\u1eabu s\u1ed1 li\u1ec7u th\u01b0\u1eddng, m\u1eabu gh\u00e9p nh\u00f3m, c\u00e1ch t\u00ednh b\u1eb1ng Excel v\u00e0 v\u00ed d\u1ee5 c\u00f3 l\u1eddi gi\u1ea3i.<\/p>\n<h2>Ph\u01b0\u01a1ng sai l\u00e0 g\u00ec?<\/h2>\n<p>Ph\u01b0\u01a1ng sai (ti\u1ebfng Anh: variance) l\u00e0 \u0111\u1ea1i l\u01b0\u1ee3ng cho bi\u1ebft c\u00e1c gi\u00e1 tr\u1ecb trong m\u1ed9t m\u1eabu s\u1ed1 li\u1ec7u &#8220;r\u1ea3i&#8221; xa gi\u00e1 tr\u1ecb trung b\u00ecnh \u0111\u1ebfn m\u1ee9c n\u00e0o. Hai nh\u00f3m d\u1eef li\u1ec7u c\u00f3 th\u1ec3 c\u00f3 c\u00f9ng trung b\u00ecnh nh\u01b0ng ph\u01b0\u01a1ng sai r\u1ea5t kh\u00e1c nhau: nh\u00f3m c\u00f3 ph\u01b0\u01a1ng sai nh\u1ecf th\u00ec c\u00e1c gi\u00e1 tr\u1ecb s\u00e1t nhau, nh\u00f3m c\u00f3 ph\u01b0\u01a1ng sai l\u1edbn th\u00ec ch\u00eanh l\u1ec7ch nhi\u1ec1u.<\/p>\n<p>Trong ch\u01b0\u01a1ng tr\u00ecnh ph\u1ed5 th\u00f4ng m\u1edbi, ph\u01b0\u01a1ng sai v\u00e0 \u0111\u1ed9 l\u1ec7ch chu\u1ea9n c\u1ee7a m\u1eabu s\u1ed1 li\u1ec7u \u0111\u01b0\u1ee3c h\u1ecdc \u1edf To\u00e1n 10; ph\u01b0\u01a1ng sai c\u1ee7a m\u1eabu s\u1ed1 li\u1ec7u gh\u00e9p nh\u00f3m h\u1ecdc \u1edf To\u00e1n 11. K\u00fd hi\u1ec7u th\u01b0\u1eddng d\u00f9ng l\u00e0 s\u00b2 (cho m\u1eabu s\u1ed1 li\u1ec7u) v\u00e0 \u03c3\u00b2 (cho t\u1ed5ng th\u1ec3 ho\u1eb7c bi\u1ebfn ng\u1eabu nhi\u00ean).<\/p>\n<p>\u0110\u1ec3 t\u00ednh ph\u01b0\u01a1ng sai, tr\u01b0\u1edbc h\u1ebft c\u1ea7n t\u00ednh trung b\u00ecnh c\u1ed9ng; n\u1ebfu c\u1ea7n \u00f4n l\u1ea1i, xem b\u00e0i <a href=\"https:\/\/hoanghamobile.com\/tin-tuc\/trung-binh-cong-la-gi\/\">trung b\u00ecnh c\u1ed9ng l\u00e0 g\u00ec<\/a>.<\/p>\n<p><img fetchpriority=\"high\" decoding=\"async\" class=\"size-full wp-image-622430 aligncenter\" src=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-1.jpg\" alt=\"phuong-sai-1\" width=\"800\" height=\"450\" srcset=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-1.jpg 800w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-1-300x169.jpg 300w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-1-768x432.jpg 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/p>\n<h2>C\u00f4ng th\u1ee9c t\u00ednh ph\u01b0\u01a1ng sai v\u00e0 \u0111\u1ed9 l\u1ec7ch chu\u1ea9n<\/h2>\n<p>V\u1edbi m\u1eabu s\u1ed1 li\u1ec7u x\u2081, x\u2082, \u2026, x\u2099 c\u00f3 trung b\u00ecnh x\u0304, ph\u01b0\u01a1ng sai \u0111\u01b0\u1ee3c t\u00ednh b\u1eb1ng trung b\u00ecnh c\u1ed9ng b\u00ecnh ph\u01b0\u01a1ng c\u00e1c \u0111\u1ed9 l\u1ec7ch so v\u1edbi x\u0304, v\u00e0 \u0111\u1ed9 l\u1ec7ch chu\u1ea9n l\u00e0 c\u0103n b\u1eadc hai c\u1ee7a ph\u01b0\u01a1ng sai.<\/p>\n<table>\n<thead>\n<tr>\n<th>\u0110\u1ea1i l\u01b0\u1ee3ng<\/th>\n<th>C\u00f4ng th\u1ee9c<\/th>\n<th>Ghi ch\u00fa<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>S\u1ed1 trung b\u00ecnh<\/td>\n<td>x\u0304 = (x\u2081 + x\u2082 + \u2026 + x\u2099) \/ n<\/td>\n<td>T\u00ednh tr\u01b0\u1edbc ti\u00ean<\/td>\n<\/tr>\n<tr>\n<td>Ph\u01b0\u01a1ng sai (\u0111\u1ecbnh ngh\u0129a)<\/td>\n<td>s\u00b2 = [(x\u2081 \u2212 x\u0304)\u00b2 + \u2026 + (x\u2099 \u2212 x\u0304)\u00b2] \/ n<\/td>\n<td>D\u1ec5 hi\u1ec3u \u00fd ngh\u0129a<\/td>\n<\/tr>\n<tr>\n<td>Ph\u01b0\u01a1ng sai (c\u00f4ng th\u1ee9c t\u00ednh nhanh)<\/td>\n<td>s\u00b2 = (x\u2081\u00b2 + x\u2082\u00b2 + \u2026 + x\u2099\u00b2) \/ n \u2212 x\u0304\u00b2<\/td>\n<td>Ti\u1ec7n khi t\u00ednh tay, m\u00e1y t\u00ednh c\u1ea7m tay<\/td>\n<\/tr>\n<tr>\n<td>\u0110\u1ed9 l\u1ec7ch chu\u1ea9n<\/td>\n<td>s = \u221as\u00b2<\/td>\n<td>C\u00f9ng \u0111\u01a1n v\u1ecb v\u1edbi d\u1eef li\u1ec7u<\/td>\n<\/tr>\n<tr>\n<td>Ph\u01b0\u01a1ng sai hi\u1ec7u ch\u1ec9nh (m\u1eabu)<\/td>\n<td>\u015d\u00b2 = \u03a3(x\u1d62 \u2212 x\u0304)\u00b2 \/ (n \u2212 1)<\/td>\n<td>D\u00f9ng khi \u01b0\u1edbc l\u01b0\u1ee3ng ph\u01b0\u01a1ng sai t\u1ed5ng th\u1ec3 t\u1eeb m\u1ed9t m\u1eabu<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>S\u00e1ch gi\u00e1o khoa ph\u1ed5 th\u00f4ng d\u00f9ng c\u00f4ng th\u1ee9c chia cho n. Trong th\u1ed1ng k\u00ea \u1ee9ng d\u1ee5ng, khi d\u00f9ng m\u1eabu \u0111\u1ec3 \u01b0\u1edbc l\u01b0\u1ee3ng t\u1ed5ng th\u1ec3, ng\u01b0\u1eddi ta th\u01b0\u1eddng chia cho n \u2212 1 (ph\u01b0\u01a1ng sai m\u1eabu hi\u1ec7u ch\u1ec9nh).<\/p>\n<p><img decoding=\"async\" class=\"size-full wp-image-622431 aligncenter\" src=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-2.jpg\" alt=\"phuong-sai-2\" width=\"800\" height=\"450\" srcset=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-2.jpg 800w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-2-300x169.jpg 300w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-2-768x432.jpg 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/p>\n<h2>V\u00ed d\u1ee5 t\u00ednh ph\u01b0\u01a1ng sai c\u00f3 l\u1eddi gi\u1ea3i<\/h2>\n<p>H\u00e3y l\u00e0m theo 4 b\u01b0\u1edbc: t\u00ednh trung b\u00ecnh, t\u00ednh t\u1eebng \u0111\u1ed9 l\u1ec7ch, b\u00ecnh ph\u01b0\u01a1ng r\u1ed3i c\u1ed9ng l\u1ea1i, chia cho n \u0111\u1ec3 c\u00f3 ph\u01b0\u01a1ng sai v\u00e0 l\u1ea5y c\u0103n \u0111\u1ec3 c\u00f3 \u0111\u1ed9 l\u1ec7ch chu\u1ea9n.<\/p>\n<p>V\u00ed d\u1ee5 1: T\u00ednh ph\u01b0\u01a1ng sai v\u00e0 \u0111\u1ed9 l\u1ec7ch chu\u1ea9n c\u1ee7a m\u1eabu s\u1ed1 li\u1ec7u: 2, 4, 4, 4, 5, 5, 7, 9.<\/p>\n<ul>\n<li>Trung b\u00ecnh: x\u0304 = (2 + 4 + 4 + 4 + 5 + 5 + 7 + 9) \/ 8 = 40 \/ 8 = 5.<\/li>\n<li>B\u00ecnh ph\u01b0\u01a1ng \u0111\u1ed9 l\u1ec7ch: 9, 1, 1, 1, 0, 0, 4, 16; t\u1ed5ng b\u1eb1ng 32.<\/li>\n<li>Ph\u01b0\u01a1ng sai: s\u00b2 = 32 \/ 8 = 4.<\/li>\n<li>\u0110\u1ed9 l\u1ec7ch chu\u1ea9n: s = \u221a4 = 2.<\/li>\n<\/ul>\n<p>N\u1ebfu d\u00f9ng ph\u01b0\u01a1ng sai hi\u1ec7u ch\u1ec9nh (chia n \u2212 1 = 7), k\u1ebft qu\u1ea3 l\u00e0 32 \/ 7 \u2248 4,571 v\u00e0 \u0111\u1ed9 l\u1ec7ch chu\u1ea9n \u2248 2,138.<\/p>\n<p>V\u00ed d\u1ee5 2 (so s\u00e1nh hai nh\u00f3m): \u0110i\u1ec3m ki\u1ec3m tra c\u1ee7a 10 h\u1ecdc sinh t\u1ed5 A: 6, 7, 7, 8, 8, 8, 9, 9, 10, 8. T\u1ed5 B: 4, 5, 6, 8, 9, 10, 10, 10, 8, 10. T\u1ed5 n\u00e0o h\u1ecdc \u0111\u1ec1u h\u01a1n?<\/p>\n<table>\n<thead>\n<tr>\n<th>T\u1ed5<\/th>\n<th>Trung b\u00ecnh<\/th>\n<th>Ph\u01b0\u01a1ng sai<\/th>\n<th>\u0110\u1ed9 l\u1ec7ch chu\u1ea9n<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>A<\/td>\n<td>8<\/td>\n<td>1,2<\/td>\n<td>\u2248 1,10<\/td>\n<\/tr>\n<tr>\n<td>B<\/td>\n<td>8<\/td>\n<td>4,6<\/td>\n<td>\u2248 2,14<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Hai t\u1ed5 c\u00f9ng trung b\u00ecnh 8 \u0111i\u1ec3m, nh\u01b0ng ph\u01b0\u01a1ng sai t\u1ed5 A nh\u1ecf h\u01a1n nhi\u1ec1u, ngh\u0129a l\u00e0 \u0111i\u1ec3m t\u1ed5 A \u0111\u1ed3ng \u0111\u1ec1u h\u01a1n; t\u1ed5 B c\u00f3 c\u1ea3 h\u1ecdc sinh r\u1ea5t cao v\u00e0 r\u1ea5t th\u1ea5p.<\/p>\n<p><img decoding=\"async\" class=\"size-full wp-image-622432 aligncenter\" src=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-3.jpg\" alt=\"phuong-sai-3\" width=\"800\" height=\"450\" srcset=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-3.jpg 800w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-3-300x169.jpg 300w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-3-768x432.jpg 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/p>\n<h2>C\u00e1ch t\u00ednh ph\u01b0\u01a1ng sai c\u1ee7a m\u1eabu s\u1ed1 li\u1ec7u gh\u00e9p nh\u00f3m<\/h2>\n<p>V\u1edbi m\u1eabu s\u1ed1 li\u1ec7u gh\u00e9p nh\u00f3m, l\u1ea5y gi\u00e1 tr\u1ecb \u0111\u1ea1i di\u1ec7n c\u1d62 (trung \u0111i\u1ec3m) c\u1ee7a m\u1ed7i nh\u00f3m, nh\u00e2n v\u1edbi t\u1ea7n s\u1ed1 n\u1d62: s\u00b2 = [n\u2081(c\u2081 \u2212 x\u0304)\u00b2 + n\u2082(c\u2082 \u2212 x\u0304)\u00b2 + \u2026 + n\u2096(c\u2096 \u2212 x\u0304)\u00b2] \/ n, trong \u0111\u00f3 x\u0304 = (n\u2081c\u2081 + \u2026 + n\u2096c\u2096) \/ n.<\/p>\n<p>V\u00ed d\u1ee5 3: Chi\u1ec1u cao (cm) c\u1ee7a 30 h\u1ecdc sinh \u0111\u01b0\u1ee3c gh\u00e9p nh\u00f3m nh\u01b0 sau:<\/p>\n<table>\n<thead>\n<tr>\n<th>Nh\u00f3m chi\u1ec1u cao<\/th>\n<th>[150; 160)<\/th>\n<th>[160; 170)<\/th>\n<th>[170; 180)<\/th>\n<th>[180; 190)<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Gi\u00e1 tr\u1ecb \u0111\u1ea1i di\u1ec7n c\u1d62<\/td>\n<td>155<\/td>\n<td>165<\/td>\n<td>175<\/td>\n<td>185<\/td>\n<\/tr>\n<tr>\n<td>T\u1ea7n s\u1ed1 n\u1d62<\/td>\n<td>5<\/td>\n<td>12<\/td>\n<td>8<\/td>\n<td>5<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<ul>\n<li>Trung b\u00ecnh: x\u0304 = (5\u00b7155 + 12\u00b7165 + 8\u00b7175 + 5\u00b7185) \/ 30 = 5.080 \/ 30 \u2248 169,33 cm.<\/li>\n<li>D\u00f9ng c\u00f4ng th\u1ee9c t\u00ednh nhanh: \u03a3n\u1d62c\u1d62\u00b2 \/ n = 862.950 \/ 30 = 28.765.<\/li>\n<li>Ph\u01b0\u01a1ng sai: s\u00b2 = 28.765 \u2212 169,33\u00b2 \u2248 91,22.<\/li>\n<li>\u0110\u1ed9 l\u1ec7ch chu\u1ea9n: s \u2248 9,55 cm.<\/li>\n<\/ul>\n<p>Khi t\u00ednh x\u0304\u00b2 n\u00ean gi\u1eef nhi\u1ec1u ch\u1eef s\u1ed1 th\u1eadp ph\u00e2n (x\u0304 = 5.080\/30) r\u1ed3i m\u1edbi l\u00e0m tr\u00f2n k\u1ebft qu\u1ea3 cu\u1ed1i \u0111\u1ec3 tr\u00e1nh sai s\u1ed1.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-622433 aligncenter\" src=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-4.jpg\" alt=\"phuong-sai-4\" width=\"800\" height=\"450\" srcset=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-4.jpg 800w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-4-300x169.jpg 300w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-4-768x432.jpg 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/p>\n<h2>C\u00e1ch t\u00ednh ph\u01b0\u01a1ng sai b\u1eb1ng Excel<\/h2>\n<p>Trong Excel, d\u00f9ng h\u00e0m VAR.P \u0111\u1ec3 t\u00ednh ph\u01b0\u01a1ng sai chia cho n (nh\u01b0 s\u00e1ch gi\u00e1o khoa), VAR.S \u0111\u1ec3 t\u00ednh ph\u01b0\u01a1ng sai m\u1eabu chia cho n \u2212 1; \u0111\u1ed9 l\u1ec7ch chu\u1ea9n t\u01b0\u01a1ng \u1ee9ng l\u00e0 STDEV.P v\u00e0 STDEV.S.<\/p>\n<ol>\n<li>Nh\u1eadp d\u1eef li\u1ec7u v\u00e0o m\u1ed9t c\u1ed9t, v\u00ed d\u1ee5 A1:A8.<\/li>\n<li>G\u00f5 <code>=VAR.P(A1:A8)<\/code> \u0111\u1ec3 c\u00f3 ph\u01b0\u01a1ng sai theo c\u00f4ng th\u1ee9c chia n.<\/li>\n<li>G\u00f5 <code>=VAR.S(A1:A8)<\/code> n\u1ebfu c\u1ea7n ph\u01b0\u01a1ng sai m\u1eabu hi\u1ec7u ch\u1ec9nh.<\/li>\n<li>G\u00f5 <code>=STDEV.P(A1:A8)<\/code> ho\u1eb7c <code>=STDEV.S(A1:A8)<\/code> \u0111\u1ec3 c\u00f3 \u0111\u1ed9 l\u1ec7ch chu\u1ea9n.<\/li>\n<\/ol>\n<p>V\u1edbi d\u1eef li\u1ec7u \u1edf V\u00ed d\u1ee5 1, VAR.P tr\u1ea3 v\u1ec1 4 v\u00e0 VAR.S tr\u1ea3 v\u1ec1 kho\u1ea3ng 4,571. M\u00e1y t\u00ednh c\u1ea7m tay \u1edf ch\u1ebf \u0111\u1ed9 th\u1ed1ng k\u00ea c\u0169ng t\u00ednh \u0111\u01b0\u1ee3c trung b\u00ecnh, \u0111\u1ed9 l\u1ec7ch chu\u1ea9n sau khi nh\u1eadp d\u1eef li\u1ec7u v\u00e0 t\u1ea7n s\u1ed1.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-622434 aligncenter\" src=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-5.jpg\" alt=\"phuong-sai-5\" width=\"800\" height=\"450\" srcset=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-5.jpg 800w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-5-300x169.jpg 300w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-5-768x432.jpg 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/p>\n<h2>\u00dd ngh\u0129a v\u00e0 \u1ee9ng d\u1ee5ng c\u1ee7a ph\u01b0\u01a1ng sai<\/h2>\n<p>Ph\u01b0\u01a1ng sai cho bi\u1ebft m\u1ee9c \u0111\u1ed9 \u1ed5n \u0111\u1ecbnh, \u0111\u1ed3ng \u0111\u1ec1u c\u1ee7a d\u1eef li\u1ec7u: trong h\u1ecdc t\u1eadp l\u00e0 \u0111\u1ed9 \u0111\u1ec1u \u0111i\u1ec3m s\u1ed1, trong s\u1ea3n xu\u1ea5t l\u00e0 \u0111\u1ed9 \u1ed5n \u0111\u1ecbnh ch\u1ea5t l\u01b0\u1ee3ng, trong t\u00e0i ch\u00ednh l\u00e0 m\u1ee9c \u0111\u1ed9 r\u1ee7i ro, bi\u1ebfn \u0111\u1ed9ng c\u1ee7a l\u1ee3i nhu\u1eadn.<\/p>\n<table>\n<thead>\n<tr>\n<th>L\u0129nh v\u1ef1c<\/th>\n<th>Ph\u01b0\u01a1ng sai cho bi\u1ebft<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Gi\u00e1o d\u1ee5c<\/td>\n<td>L\u1edbp h\u1ecdc c\u00f3 \u0111\u1ed3ng \u0111\u1ec1u hay ch\u00eanh l\u1ec7ch tr\u00ecnh \u0111\u1ed9<\/td>\n<\/tr>\n<tr>\n<td>S\u1ea3n xu\u1ea5t<\/td>\n<td>K\u00edch th\u01b0\u1edbc, kh\u1ed1i l\u01b0\u1ee3ng s\u1ea3n ph\u1ea9m c\u00f3 \u1ed5n \u0111\u1ecbnh kh\u00f4ng<\/td>\n<\/tr>\n<tr>\n<td>T\u00e0i ch\u00ednh<\/td>\n<td>M\u1ee9c bi\u1ebfn \u0111\u1ed9ng gi\u00e1, r\u1ee7i ro c\u1ee7a kho\u1ea3n \u0111\u1ea7u t\u01b0<\/td>\n<\/tr>\n<tr>\n<td>Th\u1eddi ti\u1ebft<\/td>\n<td>Nhi\u1ec7t \u0111\u1ed9 m\u1ed9t n\u01a1i dao \u0111\u1ed9ng nhi\u1ec1u hay \u00edt<\/td>\n<\/tr>\n<tr>\n<td>H\u1ecdc m\u00e1y, th\u1ed1ng k\u00ea<\/td>\n<td>\u0110\u1ed9 ph\u00e2n t\u00e1n c\u1ee7a d\u1eef li\u1ec7u, sai s\u1ed1 c\u1ee7a m\u00f4 h\u00ecnh<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Trong h\u1ecdc m\u00e1y, ph\u01b0\u01a1ng sai c\u00f2n d\u00f9ng \u0111\u1ec3 chu\u1ea9n h\u00f3a d\u1eef li\u1ec7u v\u00e0 \u0111\u00e1nh gi\u00e1 m\u1ee9c &#8220;dao \u0111\u1ed9ng&#8221; c\u1ee7a m\u00f4 h\u00ecnh; xem th\u00eam <a href=\"https:\/\/hoanghamobile.com\/tin-tuc\/machine-learning-co-ban\/\">Machine Learning l\u00e0 g\u00ec<\/a>.<\/p>\n<p>Ph\u01b0\u01a1ng sai c\u0169ng xu\u1ea5t hi\u1ec7n trong l\u00fd thuy\u1ebft x\u00e1c su\u1ea5t v\u1edbi bi\u1ebfn ng\u1eabu nhi\u00ean: Var(X) = E(X\u00b2) \u2212 [E(X)]\u00b2. B\u1ea1n c\u00f3 th\u1ec3 \u00f4n kh\u00e1i ni\u1ec7m n\u1ec1n t\u1ea3ng trong b\u00e0i <a href=\"https:\/\/hoanghamobile.com\/tin-tuc\/xac-suat-la-gi\/\">x\u00e1c su\u1ea5t l\u00e0 g\u00ec<\/a>. Mu\u1ed1n th\u1ea5y x\u00e1c su\u1ea5t \u00e1p d\u1ee5ng v\u00e0o t\u00ednh to\u00e1n th\u1ebf n\u00e0o, xem th\u00eam <a href=\"https:\/\/hoanghamobile.com\/tin-tuc\/cong-thuc-bayes\/\">c\u00f4ng th\u1ee9c Bayes<\/a> k\u00e8m v\u00ed d\u1ee5 c\u00f3 l\u1eddi gi\u1ea3i.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-622435 aligncenter\" src=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-6.jpg\" alt=\"phuong-sai-6\" width=\"800\" height=\"450\" srcset=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-6.jpg 800w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-6-300x169.jpg 300w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-6-768x432.jpg 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/p>\n<h2>L\u1ed7i th\u01b0\u1eddng g\u1eb7p khi t\u00ednh ph\u01b0\u01a1ng sai<\/h2>\n<p>C\u00e1c l\u1ed7i hay g\u1eb7p l\u00e0 qu\u00ean b\u00ecnh ph\u01b0\u01a1ng \u0111\u1ed9 l\u1ec7ch, chia nh\u1ea7m n \u2212 1 khi \u0111\u1ec1 y\u00eau c\u1ea7u theo s\u00e1ch gi\u00e1o khoa, l\u00e0m tr\u00f2n trung b\u00ecnh qu\u00e1 s\u1edbm v\u00e0 qu\u00ean nh\u00e2n t\u1ea7n s\u1ed1 v\u1edbi m\u1eabu gh\u00e9p nh\u00f3m.<\/p>\n<ul>\n<li>C\u1ed9ng \u0111\u1ed9 l\u1ec7ch kh\u00f4ng b\u00ecnh ph\u01b0\u01a1ng: t\u1ed5ng c\u00e1c \u0111\u1ed9 l\u1ec7ch lu\u00f4n b\u1eb1ng 0, n\u00ean ph\u1ea3i b\u00ecnh ph\u01b0\u01a1ng.<\/li>\n<li>Nh\u1ea7m ph\u01b0\u01a1ng sai v\u1edbi \u0111\u1ed9 l\u1ec7ch chu\u1ea9n: \u0111\u1ed9 l\u1ec7ch chu\u1ea9n l\u00e0 c\u0103n c\u1ee7a ph\u01b0\u01a1ng sai.<\/li>\n<li>\u0110\u01a1n v\u1ecb: ph\u01b0\u01a1ng sai c\u00f3 \u0111\u01a1n v\u1ecb b\u00ecnh ph\u01b0\u01a1ng (cm\u00b2), \u0111\u1ed9 l\u1ec7ch chu\u1ea9n c\u00f9ng \u0111\u01a1n v\u1ecb d\u1eef li\u1ec7u (cm).<\/li>\n<li>Ph\u01b0\u01a1ng sai kh\u00f4ng \u00e2m: n\u1ebfu ra s\u1ed1 \u00e2m, ch\u1eafc ch\u1eafn \u0111\u00e3 t\u00ednh sai.<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-622436 aligncenter\" src=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-7.jpg\" alt=\"phuong-sai-7\" width=\"800\" height=\"450\" srcset=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-7.jpg 800w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-7-300x169.jpg 300w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai-7-768x432.jpg 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/p>\n<h2>C\u00e2u h\u1ecfi th\u01b0\u1eddng g\u1eb7p v\u1ec1 ph\u01b0\u01a1ng sai<\/h2>\n<h3>Ph\u01b0\u01a1ng sai l\u00e0 g\u00ec?<\/h3>\n<p>Ph\u01b0\u01a1ng sai l\u00e0 trung b\u00ecnh c\u1ed9ng b\u00ecnh ph\u01b0\u01a1ng c\u00e1c \u0111\u1ed9 l\u1ec7ch c\u1ee7a d\u1eef li\u1ec7u so v\u1edbi s\u1ed1 trung b\u00ecnh, cho bi\u1ebft d\u1eef li\u1ec7u ph\u00e2n t\u00e1n nhi\u1ec1u hay \u00edt quanh trung b\u00ecnh.<\/p>\n<h3>Ph\u01b0\u01a1ng sai v\u00e0 \u0111\u1ed9 l\u1ec7ch chu\u1ea9n kh\u00e1c nhau th\u1ebf n\u00e0o?<\/h3>\n<p>\u0110\u1ed9 l\u1ec7ch chu\u1ea9n l\u00e0 c\u0103n b\u1eadc hai c\u1ee7a ph\u01b0\u01a1ng sai. \u0110\u1ed9 l\u1ec7ch chu\u1ea9n c\u00f9ng \u0111\u01a1n v\u1ecb v\u1edbi d\u1eef li\u1ec7u n\u00ean d\u1ec5 di\u1ec5n gi\u1ea3i h\u01a1n, c\u00f2n ph\u01b0\u01a1ng sai c\u00f3 \u0111\u01a1n v\u1ecb b\u00ecnh ph\u01b0\u01a1ng.<\/p>\n<h3>Ph\u01b0\u01a1ng sai c\u00f3 th\u1ec3 \u00e2m kh\u00f4ng?<\/h3>\n<p>Kh\u00f4ng. Ph\u01b0\u01a1ng sai l\u00e0 t\u1ed5ng c\u00e1c b\u00ecnh ph\u01b0\u01a1ng chia cho s\u1ed1 d\u01b0\u01a1ng n\u00ean lu\u00f4n l\u1edbn h\u01a1n ho\u1eb7c b\u1eb1ng 0; b\u1eb1ng 0 khi m\u1ecdi gi\u00e1 tr\u1ecb b\u1eb1ng nhau.<\/p>\n<h3>Khi n\u00e0o chia cho n, khi n\u00e0o chia cho n \u2212 1?<\/h3>\n<p>S\u00e1ch gi\u00e1o khoa ph\u1ed5 th\u00f4ng chia cho n. Khi d\u00f9ng m\u1ed9t m\u1eabu \u0111\u1ec3 \u01b0\u1edbc l\u01b0\u1ee3ng ph\u01b0\u01a1ng sai c\u1ee7a t\u1ed5ng th\u1ec3, th\u1ed1ng k\u00ea th\u01b0\u1eddng chia cho n \u2212 1.<\/p>\n<h3>Ph\u01b0\u01a1ng sai h\u1ecdc l\u1edbp m\u1ea5y?<\/h3>\n<p>Theo ch\u01b0\u01a1ng tr\u00ecnh m\u1edbi, ph\u01b0\u01a1ng sai v\u00e0 \u0111\u1ed9 l\u1ec7ch chu\u1ea9n c\u1ee7a m\u1eabu s\u1ed1 li\u1ec7u h\u1ecdc \u1edf To\u00e1n 10, c\u1ee7a m\u1eabu s\u1ed1 li\u1ec7u gh\u00e9p nh\u00f3m h\u1ecdc \u1edf To\u00e1n 11.<\/p>\n<h3>H\u00e0m t\u00ednh ph\u01b0\u01a1ng sai trong Excel l\u00e0 g\u00ec?<\/h3>\n<p>D\u00f9ng VAR.P cho ph\u01b0\u01a1ng sai chia n, VAR.S cho ph\u01b0\u01a1ng sai m\u1eabu chia n \u2212 1; \u0111\u1ed9 l\u1ec7ch chu\u1ea9n d\u00f9ng STDEV.P v\u00e0 STDEV.S.<\/p>\n<h2>K\u1ebft lu\u1eadn<\/h2>\n<p>Ph\u01b0\u01a1ng sai \u0111o m\u1ee9c \u0111\u1ed9 ph\u00e2n t\u00e1n c\u1ee7a d\u1eef li\u1ec7u quanh trung b\u00ecnh, t\u00ednh b\u1eb1ng trung b\u00ecnh c\u1ed9ng b\u00ecnh ph\u01b0\u01a1ng c\u00e1c \u0111\u1ed9 l\u1ec7ch; \u0111\u1ed9 l\u1ec7ch chu\u1ea9n l\u00e0 c\u0103n b\u1eadc hai c\u1ee7a n\u00f3. Nh\u1edb c\u00f4ng th\u1ee9c t\u00ednh nhanh s\u00b2 = trung b\u00ecnh b\u00ecnh ph\u01b0\u01a1ng tr\u1eeb b\u00ecnh ph\u01b0\u01a1ng trung b\u00ecnh, d\u00f9ng gi\u00e1 tr\u1ecb \u0111\u1ea1i di\u1ec7n v\u00e0 t\u1ea7n s\u1ed1 cho m\u1eabu gh\u00e9p nh\u00f3m, v\u00e0 d\u00f9ng VAR.P ho\u1eb7c VAR.S trong Excel t\u00f9y y\u00eau c\u1ea7u \u0111\u1ec1 b\u00e0i l\u00e0 b\u1ea1n \u0111\u1ee7 x\u1eed l\u00fd m\u1ecdi d\u1ea1ng b\u00e0i ph\u01b0\u01a1ng sai ph\u1ed5 th\u00f4ng.<\/p>\n<p><strong>Xem th\u00eam:\u00a0<\/strong><\/p>\n<ul>\n<li class=\"elementor-heading-title elementor-size-default\"><a href=\"https:\/\/hoanghamobile.com\/tin-tuc\/cong-thuc-to-hop-chinh-hop\/\">B\u1ed9 c\u00f4ng th\u1ee9c Ho\u00e1n v\u1ecb \u2013 Ch\u1ec9nh h\u1ee3p \u2013 T\u1ed5 h\u1ee3p \u0111\u1ea7y \u0111\u1ee7 nh\u1ea5t trong To\u00e1n h\u1ecdc<\/a><\/li>\n<li class=\"elementor-heading-title elementor-size-default\"><a href=\"https:\/\/hoanghamobile.com\/tin-tuc\/tap-hop-so-nguyen-z-la-gi-giai-ma-toan-dien-ve-z-trong-toan-hoc\/\">T\u1eadp h\u1ee3p s\u1ed1 nguy\u00ean Z l\u00e0 g\u00ec? Gi\u1ea3i m\u00e3 to\u00e0n di\u1ec7n v\u1ec1 Z trong To\u00e1n h\u1ecdc<\/a><\/li>\n<\/ul>\n<p><script type=\"application\/ld+json\">{\"@context\":\"https:\/\/schema.org\",\"@type\":\"FAQPage\",\"mainEntity\":[{\"@type\":\"Question\",\"name\":\"Ph\u01b0\u01a1ng sai l\u00e0 g\u00ec?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Ph\u01b0\u01a1ng sai l\u00e0 trung b\u00ecnh c\u1ed9ng b\u00ecnh ph\u01b0\u01a1ng c\u00e1c \u0111\u1ed9 l\u1ec7ch c\u1ee7a d\u1eef li\u1ec7u so v\u1edbi s\u1ed1 trung b\u00ecnh, cho bi\u1ebft d\u1eef li\u1ec7u ph\u00e2n t\u00e1n nhi\u1ec1u hay \u00edt quanh trung b\u00ecnh.\"}},{\"@type\":\"Question\",\"name\":\"Ph\u01b0\u01a1ng sai v\u00e0 \u0111\u1ed9 l\u1ec7ch chu\u1ea9n kh\u00e1c nhau th\u1ebf n\u00e0o?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"\u0110\u1ed9 l\u1ec7ch chu\u1ea9n l\u00e0 c\u0103n b\u1eadc hai c\u1ee7a ph\u01b0\u01a1ng sai. \u0110\u1ed9 l\u1ec7ch chu\u1ea9n c\u00f9ng \u0111\u01a1n v\u1ecb v\u1edbi d\u1eef li\u1ec7u n\u00ean d\u1ec5 di\u1ec5n gi\u1ea3i h\u01a1n, c\u00f2n ph\u01b0\u01a1ng sai c\u00f3 \u0111\u01a1n v\u1ecb b\u00ecnh ph\u01b0\u01a1ng.\"}},{\"@type\":\"Question\",\"name\":\"Ph\u01b0\u01a1ng sai c\u00f3 th\u1ec3 \u00e2m kh\u00f4ng?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Kh\u00f4ng. Ph\u01b0\u01a1ng sai l\u00e0 t\u1ed5ng c\u00e1c b\u00ecnh ph\u01b0\u01a1ng chia cho s\u1ed1 d\u01b0\u01a1ng n\u00ean lu\u00f4n l\u1edbn h\u01a1n ho\u1eb7c b\u1eb1ng 0; b\u1eb1ng 0 khi m\u1ecdi gi\u00e1 tr\u1ecb b\u1eb1ng nhau.\"}},{\"@type\":\"Question\",\"name\":\"Khi n\u00e0o chia cho n, khi n\u00e0o chia cho n \u2212 1?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"S\u00e1ch gi\u00e1o khoa ph\u1ed5 th\u00f4ng chia cho n. Khi d\u00f9ng m\u1ed9t m\u1eabu \u0111\u1ec3 \u01b0\u1edbc l\u01b0\u1ee3ng ph\u01b0\u01a1ng sai c\u1ee7a t\u1ed5ng th\u1ec3, th\u1ed1ng k\u00ea th\u01b0\u1eddng chia cho n \u2212 1.\"}},{\"@type\":\"Question\",\"name\":\"Ph\u01b0\u01a1ng sai h\u1ecdc l\u1edbp m\u1ea5y?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Theo ch\u01b0\u01a1ng tr\u00ecnh m\u1edbi, ph\u01b0\u01a1ng sai v\u00e0 \u0111\u1ed9 l\u1ec7ch chu\u1ea9n c\u1ee7a m\u1eabu s\u1ed1 li\u1ec7u h\u1ecdc \u1edf To\u00e1n 10, c\u1ee7a m\u1eabu s\u1ed1 li\u1ec7u gh\u00e9p nh\u00f3m h\u1ecdc \u1edf To\u00e1n 11.\"}},{\"@type\":\"Question\",\"name\":\"H\u00e0m t\u00ednh ph\u01b0\u01a1ng sai trong Excel l\u00e0 g\u00ec?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"D\u00f9ng VAR.P cho ph\u01b0\u01a1ng sai chia n, VAR.S cho ph\u01b0\u01a1ng sai m\u1eabu chia n \u2212 1; \u0111\u1ed9 l\u1ec7ch chu\u1ea9n d\u00f9ng STDEV.P v\u00e0 STDEV.S.\"}}]}<\/script><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Ph\u01b0\u01a1ng sai l\u00e0 s\u1ed1 \u0111o m\u1ee9c \u0111\u1ed9 ph\u00e2n t\u00e1n c\u1ee7a d\u1eef li\u1ec7u quanh gi\u00e1 tr\u1ecb trung b\u00ecnh, b\u1eb1ng trung b\u00ecnh c\u1ed9ng b\u00ecnh ph\u01b0\u01a1ng c\u00e1c \u0111\u1ed9 l\u1ec7ch: s\u00b2 = [(x\u2081 \u2212 x\u0304)\u00b2 + (x\u2082 \u2212 x\u0304)\u00b2 + \u2026 + (x\u2099 \u2212 x\u0304)\u00b2] \/ n. Ph\u01b0\u01a1ng sai c\u00e0ng l\u1edbn, d\u1eef li\u1ec7u c\u00e0ng ph\u00e2n t\u00e1n; c\u0103n b\u1eadc hai [&hellip;]<\/p>\n","protected":false},"author":65,"featured_media":622428,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_yoast_wpseo_focuskw":"ph\u01b0\u01a1ng sai","_yoast_wpseo_title":"Ph\u01b0\u01a1ng sai l\u00e0 g\u00ec? C\u00f4ng th\u1ee9c, c\u00e1ch t\u00ednh v\u00e0 v\u00ed d\u1ee5 chi ti\u1ebft","_yoast_wpseo_metadesc":"Ph\u01b0\u01a1ng sai l\u00e0 g\u00ec? Xem c\u00f4ng th\u1ee9c t\u00ednh ph\u01b0\u01a1ng sai, \u0111\u1ed9 l\u1ec7ch chu\u1ea9n, c\u00e1ch t\u00ednh cho m\u1eabu gh\u00e9p nh\u00f3m, b\u1eb1ng Excel k\u00e8m v\u00ed d\u1ee5 c\u00f3 l\u1eddi gi\u1ea3i v\u00e0 \u00e1p d\u1ee5ng ngay.","footnotes":""},"categories":[29235,3910,30453],"tags":[],"class_list":["post-620587","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-goc-to-mo","category-kham-pha","category-kien-thuc"],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v27.3 (Yoast SEO v27.4) - https:\/\/yoast.com\/product\/yoast-seo-premium-wordpress\/ -->\n<title>Ph\u01b0\u01a1ng sai l\u00e0 g\u00ec? C\u00f4ng th\u1ee9c, c\u00e1ch t\u00ednh v\u00e0 v\u00ed d\u1ee5 chi ti\u1ebft<\/title>\n<meta name=\"description\" content=\"Ph\u01b0\u01a1ng sai l\u00e0 g\u00ec? Xem c\u00f4ng th\u1ee9c t\u00ednh ph\u01b0\u01a1ng sai, \u0111\u1ed9 l\u1ec7ch chu\u1ea9n, c\u00e1ch t\u00ednh cho m\u1eabu gh\u00e9p nh\u00f3m, b\u1eb1ng Excel k\u00e8m v\u00ed d\u1ee5 c\u00f3 l\u1eddi gi\u1ea3i v\u00e0 \u00e1p d\u1ee5ng ngay.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/hoanghamobile.com\/tin-tuc\/phuong-sai\/\" \/>\n<meta property=\"og:locale\" content=\"vi_VN\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Ph\u01b0\u01a1ng sai l\u00e0 g\u00ec? C\u00f4ng th\u1ee9c, c\u00e1ch t\u00ednh v\u00e0 v\u00ed d\u1ee5 c\u00f3 l\u1eddi gi\u1ea3i\" \/>\n<meta property=\"og:description\" content=\"Ph\u01b0\u01a1ng sai l\u00e0 g\u00ec? Xem c\u00f4ng th\u1ee9c t\u00ednh ph\u01b0\u01a1ng sai, \u0111\u1ed9 l\u1ec7ch chu\u1ea9n, c\u00e1ch t\u00ednh cho m\u1eabu gh\u00e9p nh\u00f3m, b\u1eb1ng Excel k\u00e8m v\u00ed d\u1ee5 c\u00f3 l\u1eddi gi\u1ea3i v\u00e0 \u00e1p d\u1ee5ng ngay.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/hoanghamobile.com\/tin-tuc\/phuong-sai\/\" \/>\n<meta property=\"og:site_name\" content=\"Tin t\u1ee9c c\u00f4ng ngh\u1ec7 - HoangHaMobile\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/hoanghamobilecom\" \/>\n<meta property=\"article:author\" content=\"https:\/\/www.facebook.com\/hoanghamobilecom\" \/>\n<meta property=\"article:published_time\" content=\"2026-11-09T02:17:34+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2026-11-09T02:18:03+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/11\/phuong-sai.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"1200\" \/>\n\t<meta property=\"og:image:height\" content=\"628\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"author\" content=\"Vo Giang\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"\u0110\u01b0\u1ee3c vi\u1ebft b\u1edfi\" \/>\n\t<meta name=\"twitter:data1\" content=\"Vo Giang\" \/>\n\t<meta name=\"twitter:label2\" content=\"\u01af\u1edbc t\u00ednh th\u1eddi gian \u0111\u1ecdc\" \/>\n\t<meta name=\"twitter:data2\" content=\"11 ph\u00fat\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/hoanghamobile.com\\\/tin-tuc\\\/phuong-sai\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/hoanghamobile.com\\\/tin-tuc\\\/phuong-sai\\\/\"},\"author\":{\"name\":\"Vo Giang\",\"@id\":\"https:\\\/\\\/hoanghamobile.com\\\/tin-tuc\\\/#\\\/schema\\\/person\\\/72d0493d28396e6a0cdc358e9260c03c\"},\"headline\":\"Ph\u01b0\u01a1ng sai l\u00e0 g\u00ec? C\u00f4ng th\u1ee9c, c\u00e1ch t\u00ednh v\u00e0 v\u00ed d\u1ee5 c\u00f3 l\u1eddi gi\u1ea3i\",\"datePublished\":\"2026-11-09T02:17:34+00:00\",\"dateModified\":\"2026-11-09T02:18:03+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/hoanghamobile.com\\\/tin-tuc\\\/phuong-sai\\\/\"},\"wordCount\":2095,\"publisher\":{\"@id\":\"https:\\\/\\\/hoanghamobile.com\\\/tin-tuc\\\/#organization\"},\"image\":{\"@id\":\"https:\\\/\\\/hoanghamobile.com\\\/tin-tuc\\\/phuong-sai\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/hoanghamobile.com\\\/tin-tuc\\\/wp-content\\\/uploads\\\/2026\\\/11\\\/phuong-sai.jpg\",\"articleSection\":[\"G\u00f3c t\u00f2 m\u00f2\",\"Kh\u00e1m Ph\u00e1\",\"Ki\u1ebfn Th\u1ee9c\"],\"inLanguage\":\"vi\",\"copyrightYear\":\"2026\",\"copyrightHolder\":{\"@id\":\"https:\\\/\\\/hoanghamobile.com\\\/tin-tuc\\\/#organization\"}},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/hoanghamobile.com\\\/tin-tuc\\\/phuong-sai\\\/\",\"url\":\"https:\\\/\\\/hoanghamobile.com\\\/tin-tuc\\\/phuong-sai\\\/\",\"name\":\"Ph\u01b0\u01a1ng sai l\u00e0 g\u00ec? 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