{"id":788,"date":"2023-07-22T18:35:25","date_gmt":"2023-07-22T11:35:25","guid":{"rendered":"https:\/\/tuyendung.edu.vn\/blog\/?p=788"},"modified":"2023-07-22T18:36:02","modified_gmt":"2023-07-22T11:36:02","slug":"variance-la-gi","status":"publish","type":"post","link":"https:\/\/tuyendung.edu.vn\/blog\/variance-la-gi.html","title":{"rendered":"Variance l\u00e0 g\u00ec? Kh\u00e1m ph\u00e1 kh\u00e1i ni\u1ec7m quan tr\u1ecdng trong th\u1ed1ng k\u00ea v\u00e0 t\u00e0i ch\u00ednh"},"content":{"rendered":"<div id=\"toc_container\" class=\"toc_light_blue no_bullets\"><p class=\"toc_title\">M\u1ee5c l\u1ee5c<\/p><ul class=\"toc_list\"><li><a href=\"#Variance_la_gi\"><span class=\"toc_number toc_depth_1\">1<\/span> Variance l\u00e0 g\u00ec?<\/a><ul><li><a href=\"#Dinh_nghia_variance\"><span class=\"toc_number toc_depth_2\">1.1<\/span> \u0110\u1ecbnh ngh\u0129a variance<\/a><\/li><li><a href=\"#Y_nghia_va_vai_tro_cua_variance_trong_thong_ke_va_tai_chinh\"><span class=\"toc_number toc_depth_2\">1.2<\/span> \u00dd ngh\u0129a v\u00e0 vai tr\u00f2 c\u1ee7a variance trong th\u1ed1ng k\u00ea v\u00e0 t\u00e0i ch\u00ednh<\/a><\/li><\/ul><\/li><li><a href=\"#Cach_tinh_toan_variance\"><span class=\"toc_number toc_depth_1\">2<\/span> C\u00e1ch t\u00ednh to\u00e1n variance<\/a><ul><li><a href=\"#Cong_thuc_tinh_toan_variance\"><span class=\"toc_number toc_depth_2\">2.1<\/span> C\u00f4ng th\u1ee9c t\u00ednh to\u00e1n variance<\/a><\/li><li><a href=\"#Vi_du_minh_hoa_cach_tinh_variance\"><span class=\"toc_number toc_depth_2\">2.2<\/span> V\u00ed d\u1ee5 minh h\u1ecda c\u00e1ch t\u00ednh variance<\/a><\/li><\/ul><\/li><li><a href=\"#Ung_dung_cua_variance\"><span class=\"toc_number toc_depth_1\">3<\/span> \u1ee8ng d\u1ee5ng c\u1ee7a variance<\/a><ul><li><a href=\"#Variance_trong_thong_ke\"><span class=\"toc_number toc_depth_2\">3.1<\/span> Variance trong th\u1ed1ng k\u00ea<\/a><\/li><li><a href=\"#Variance_trong_tai_chinh\"><span class=\"toc_number toc_depth_2\">3.2<\/span> Variance trong t\u00e0i ch\u00ednh<\/a><\/li><\/ul><\/li><li><a href=\"#So_sanh_variance_voi_cac_khai_niem_lien_quan\"><span class=\"toc_number toc_depth_1\">4<\/span> So s\u00e1nh variance v\u1edbi c\u00e1c kh\u00e1i ni\u1ec7m li\u00ean quan<\/a><ul><li><a href=\"#So_sanh_variance_voi_standard_deviation\"><span class=\"toc_number toc_depth_2\">4.1<\/span> So s\u00e1nh variance v\u1edbi standard deviation<\/a><\/li><li><a href=\"#So_sanh_variance_va_covariance\"><span class=\"toc_number toc_depth_2\">4.2<\/span> So s\u00e1nh variance v\u00e0 covariance<\/a><\/li><\/ul><\/li><li><a href=\"#Nhung_thach_thuc_khi_su_dung_variance\"><span class=\"toc_number toc_depth_1\">5<\/span> Nh\u1eefng th\u00e1ch th\u1ee9c khi s\u1eed d\u1ee5ng variance<\/a><ul><li><a href=\"#Anh_huong_cua_du_lieu_ngoai_lai_outliers_doi_voi_variance\"><span class=\"toc_number toc_depth_2\">5.1<\/span> \u1ea2nh h\u01b0\u1edfng c\u1ee7a d\u1eef li\u1ec7u ngo\u1ea1i lai (outliers) \u0111\u1ed1i v\u1edbi variance<\/a><\/li><li><a href=\"#Rui_ro_sai_tuong_khi_khong_hieu_ro_gia_tri_variance\"><span class=\"toc_number toc_depth_2\">5.2<\/span> R\u1ee7i ro sai t\u01b0\u1edfng khi kh\u00f4ng hi\u1ec3u r\u00f5 gi\u00e1 tr\u1ecb variance<\/a><\/li><\/ul><\/li><\/ul><\/div>\n<p style=\"text-align: justify;\">Variance (ph\u01b0\u01a1ng sai) l\u00e0 m\u1ed9t kh\u00e1i ni\u1ec7m quan tr\u1ecdng trong th\u1ed1ng k\u00ea v\u00e0 t\u00e0i ch\u00ednh, gi\u00fap \u0111o l\u01b0\u1eddng m\u1ee9c \u0111\u1ed9 bi\u1ebfn \u0111\u1ed5i c\u1ee7a d\u1eef li\u1ec7u. N\u00f3 th\u01b0\u1eddng \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 \u0111\u00e1nh gi\u00e1 s\u1ef1 ph\u00e2n t\u00e1n v\u00e0 \u0111o l\u01b0\u1eddng \u0111\u1ed9 bi\u1ebfn thi\u00ean c\u1ee7a c\u00e1c gi\u00e1 tr\u1ecb trong m\u1ed9t t\u1eadp d\u1eef li\u1ec7u. Trong b\u00e0i vi\u1ebft n\u00e0y, ch\u00fang ta s\u1ebd t\u00ecm hi\u1ec3u v\u1ec1 \u0111\u1ecbnh ngh\u0129a <strong>variance l\u00e0 g\u00ec<\/strong>, vai tr\u00f2 c\u1ee7a variance, c\u00f9ng v\u1edbi c\u00e1ch t\u00ednh to\u00e1n v\u00e0 \u1ee9ng d\u1ee5ng th\u1ef1c t\u1ebf c\u1ee7a n\u00f3 trong l\u0129nh v\u1ef1c th\u1ed1ng k\u00ea v\u00e0 t\u00e0i ch\u00ednh.<\/p>\n<p style=\"text-align: justify;\">H\u00e3y c\u00f9ng v\u1edbi <a href=\"https:\/\/tuyendung.edu.vn\/blog\/\" target=\"_blank\" rel=\"noopener\"><strong>g\u00f3c ngh\u1ec1 nghi\u1ec7p<\/strong><\/a> \u0111i s\u00e2u v\u00e0o kh\u00e1m ph\u00e1 kh\u00e1i ni\u1ec7m quan tr\u1ecdng n\u00e0y \u0111\u1ec3 hi\u1ec3u r\u00f5 h\u01a1n v\u1ec1 s\u1ef1 bi\u1ebfn \u0111\u1ed5i c\u1ee7a d\u1eef li\u1ec7u v\u00e0 t\u1ea7m quan tr\u1ecdng c\u1ee7a n\u00f3 trong c\u00e1c ph\u00e2n t\u00edch v\u00e0 quy\u1ebft \u0111\u1ecbnh kinh doanh nh\u00e9.<\/p>\n<h2 style=\"text-align: justify;\"><span id=\"Variance_la_gi\">Variance l\u00e0 g\u00ec?<\/span><\/h2>\n<figure id=\"attachment_789\" aria-describedby=\"caption-attachment-789\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-789\" src=\"https:\/\/tuyendung.edu.vn\/blog\/wp-content\/uploads\/2023\/07\/22\/Variance-la-gi.jpg\" alt=\"Variance l\u00e0 g\u00ec\" width=\"800\" height=\"533\" srcset=\"https:\/\/tuyendung.edu.vn\/blog\/wp-content\/uploads\/2023\/07\/22\/Variance-la-gi-768x512.jpg 768w, https:\/\/tuyendung.edu.vn\/blog\/wp-content\/uploads\/2023\/07\/22\/Variance-la-gi.jpg 800w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption id=\"caption-attachment-789\" class=\"wp-caption-text\">Variance l\u00e0 g\u00ec<\/figcaption><\/figure>\n<h3 style=\"text-align: justify;\"><span id=\"Dinh_nghia_variance\">\u0110\u1ecbnh ngh\u0129a variance<\/span><\/h3>\n<p style=\"text-align: justify;\">Variance l\u00e0 m\u1ed9t kh\u00e1i ni\u1ec7m trong th\u1ed1ng k\u00ea v\u00e0 t\u00e0i ch\u00ednh \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 \u0111o l\u01b0\u1eddng m\u1ee9c \u0111\u1ed9 bi\u1ebfn \u0111\u1ed5i c\u1ee7a d\u1eef li\u1ec7u trong m\u1ed9t t\u1eadp h\u1ee3p. N\u00f3 th\u1ec3 hi\u1ec7n m\u1ee9c \u0111\u1ed9 \u0111\u00e1nh r\u01a1i gi\u1eefa c\u00e1c gi\u00e1 tr\u1ecb d\u1eef li\u1ec7u so v\u1edbi gi\u00e1 tr\u1ecb trung b\u00ecnh. Khi ch\u1ec9 s\u1ed1 variance c\u00e0ng l\u1edbn, c\u00f3 ngh\u0129a l\u00e0 d\u1eef li\u1ec7u c\u00f3 s\u1ef1 bi\u1ebfn \u0111\u1ed5i l\u1edbn, trong khi khi variance nh\u1ecf h\u01a1n th\u00ec d\u1eef li\u1ec7u c\u00f3 s\u1ef1 t\u1eadp trung v\u00e0 \u1ed5n \u0111\u1ecbnh h\u01a1n.<\/p>\n<h3 style=\"text-align: justify;\"><span id=\"Y_nghia_va_vai_tro_cua_variance_trong_thong_ke_va_tai_chinh\">\u00dd ngh\u0129a v\u00e0 vai tr\u00f2 c\u1ee7a variance trong th\u1ed1ng k\u00ea v\u00e0 t\u00e0i ch\u00ednh<\/span><\/h3>\n<ul style=\"text-align: justify;\">\n<li aria-level=\"1\">\u0110\u00e1nh gi\u00e1 s\u1ef1 bi\u1ebfn \u0111\u1ed5i d\u1eef li\u1ec7u: Variance cho ph\u00e9p \u0111\u00e1nh gi\u00e1 m\u1ee9c \u0111\u1ed9 bi\u1ebfn thi\u00ean c\u1ee7a d\u1eef li\u1ec7u trong m\u1ed9t t\u1eadp h\u1ee3p. Khi th\u1ef1c hi\u1ec7n ph\u00e2n t\u00edch d\u1eef li\u1ec7u, vi\u1ec7c bi\u1ebft \u0111\u1ebfn m\u1ee9c \u0111\u1ed9 bi\u1ebfn \u0111\u1ed5i n\u00e0y gi\u00fap ta hi\u1ec3u r\u00f5 h\u01a1n v\u1ec1 t\u00ednh ch\u1ea5t v\u00e0 \u0111\u1eb7c \u0111i\u1ec3m c\u1ee7a d\u1eef li\u1ec7u, t\u1eeb \u0111\u00f3 \u0111\u01b0a ra nh\u1eefng k\u1ebft lu\u1eadn v\u00e0 quy\u1ebft \u0111\u1ecbnh ph\u00f9 h\u1ee3p.<\/li>\n<li aria-level=\"1\">\u0110o l\u01b0\u1eddng \u0111\u1ed9 bi\u1ebfn thi\u00ean: Ph\u01b0\u01a1ng sai c\u0169ng l\u00e0 m\u1ed9t ph\u01b0\u01a1ng ti\u1ec7n quan tr\u1ecdng \u0111\u1ec3 \u0111o l\u01b0\u1eddng \u0111\u1ed9 bi\u1ebfn thi\u00ean gi\u1eefa c\u00e1c t\u1eadp d\u1eef li\u1ec7u kh\u00e1c nhau. \u0110i\u1ec1u n\u00e0y h\u1ed7 tr\u1ee3 trong vi\u1ec7c so s\u00e1nh v\u00e0 l\u1ef1a ch\u1ecdn c\u00e1c t\u1eadp d\u1eef li\u1ec7u c\u00f3 t\u00ednh ch\u1ea5t g\u1ea7n gi\u1ed1ng nhau ho\u1eb7c \u1ed5n \u0111\u1ecbnh \u0111\u1ec3 ti\u1ebfn h\u00e0nh c\u00e1c ph\u00e2n t\u00edch hay quy\u1ebft \u0111\u1ecbnh kinh doanh.<\/li>\n<li aria-level=\"1\">Qu\u1ea3n l\u00fd r\u1ee7i ro trong t\u00e0i ch\u00ednh: Trong l\u0129nh v\u1ef1c t\u00e0i ch\u00ednh, variance \u0111\u00f3ng vai tr\u00f2 quan tr\u1ecdng trong vi\u1ec7c \u0111o l\u01b0\u1eddng v\u00e0 qu\u1ea3n l\u00fd r\u1ee7i ro. Khi \u0111\u1ea7u t\u01b0 ho\u1eb7c l\u00e0m vi\u1ec7c v\u1edbi t\u00e0i s\u1ea3n t\u00e0i ch\u00ednh, hi\u1ec3u r\u00f5 m\u1ee9c \u0111\u1ed9 bi\u1ebfn \u0111\u1ed5i c\u1ee7a ch\u00fang gi\u00fap \u0111\u00e1nh gi\u00e1 nguy c\u01a1 v\u00e0 l\u1ee3i \u00edch, t\u1eeb \u0111\u00f3 \u0111\u01b0a ra quy\u1ebft \u0111\u1ecbnh \u0111\u1ea7u t\u01b0 hi\u1ec7u qu\u1ea3.<\/li>\n<\/ul>\n<p style=\"text-align: justify;\">T\u00f3m l\u1ea1i, ph\u01b0\u01a1ng sai l\u00e0 m\u1ed9t kh\u00e1i ni\u1ec7m quan tr\u1ecdng trong th\u1ed1ng k\u00ea v\u00e0 t\u00e0i ch\u00ednh, gi\u00fap \u0111o l\u01b0\u1eddng v\u00e0 \u0111\u00e1nh gi\u00e1 m\u1ee9c \u0111\u1ed9 bi\u1ebfn \u0111\u1ed5i c\u1ee7a d\u1eef li\u1ec7u. Vi\u1ec7c hi\u1ec3u r\u00f5 v\u00e0 \u1ee9ng d\u1ee5ng ph\u01b0\u01a1ng sai m\u1ed9t c\u00e1ch h\u1ee3p l\u00fd trong c\u00e1c ph\u00e2n t\u00edch v\u00e0 quy\u1ebft \u0111\u1ecbnh kinh doanh l\u00e0 m\u1ed9t y\u1ebfu t\u1ed1 c\u01a1 b\u1ea3n \u0111\u1ec3 \u0111\u1ea1t \u0111\u01b0\u1ee3c hi\u1ec7u qu\u1ea3 v\u00e0 th\u00e0nh c\u00f4ng trong l\u0129nh v\u1ef1c n\u00e0y.<\/p>\n<blockquote><p>Xem th\u00eam: <a href=\"https:\/\/tuyendung.edu.vn\/blog\/business-model-la-gi.html\" target=\"_blank\" rel=\"noopener\"><strong>Business Model l\u00e0 g\u00ec? \u00dd ngh\u0129a v\u00e0 T\u1ea7m quan tr\u1ecdng trong kinh doanh<\/strong><\/a><\/p><\/blockquote>\n<h2 style=\"text-align: justify;\"><span id=\"Cach_tinh_toan_variance\">C\u00e1ch t\u00ednh to\u00e1n variance<\/span><\/h2>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-790\" src=\"https:\/\/tuyendung.edu.vn\/blog\/wp-content\/uploads\/2023\/07\/22\/variance.jpg\" alt=\"Variance\" width=\"800\" height=\"400\" srcset=\"https:\/\/tuyendung.edu.vn\/blog\/wp-content\/uploads\/2023\/07\/22\/variance-768x384.jpg 768w, https:\/\/tuyendung.edu.vn\/blog\/wp-content\/uploads\/2023\/07\/22\/variance.jpg 800w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><\/p>\n<h3 style=\"text-align: justify;\"><span id=\"Cong_thuc_tinh_toan_variance\">C\u00f4ng th\u1ee9c t\u00ednh to\u00e1n variance<\/span><\/h3>\n<p style=\"text-align: justify;\">Variance l\u00e0 m\u1ed9t ph\u01b0\u01a1ng ph\u00e1p \u0111o l\u01b0\u1eddng s\u1ef1 bi\u1ebfn \u0111\u1ed5i c\u1ee7a d\u1eef li\u1ec7u t\u1eeb gi\u00e1 tr\u1ecb trung b\u00ecnh. \u0110\u1ec3 t\u00ednh to\u00e1n variance, ta l\u00e0m nh\u01b0 sau:<\/p>\n<ul style=\"text-align: justify;\">\n<li aria-level=\"1\">T\u00ednh gi\u00e1 tr\u1ecb trung b\u00ecnh c\u1ee7a d\u1eef li\u1ec7u (mean, \u03bc).<\/li>\n<li aria-level=\"1\">T\u00ednh b\u00ecnh ph\u01b0\u01a1ng c\u1ee7a \u0111\u1ed9 sai l\u1ec7ch c\u1ee7a t\u1eebng gi\u00e1 tr\u1ecb so v\u1edbi gi\u00e1 tr\u1ecb trung b\u00ecnh.<\/li>\n<li aria-level=\"1\">T\u1ed5ng h\u1ee3p c\u00e1c b\u00ecnh ph\u01b0\u01a1ng sai l\u1ec7ch v\u00e0 chia cho s\u1ed1 l\u01b0\u1ee3ng gi\u00e1 tr\u1ecb trong t\u1eadp d\u1eef li\u1ec7u (n).<\/li>\n<\/ul>\n<p style=\"text-align: justify;\">C\u00f4ng th\u1ee9c t\u00ednh variance (\u03c3^2) nh\u01b0 sau:<\/p>\n<ul style=\"text-align: justify;\">\n<li aria-level=\"1\">\u03c3^2 = \u03a3 (xi &#8211; \u03bc)^2 \/ n<\/li>\n<\/ul>\n<p style=\"text-align: justify;\">Trong \u0111\u00f3: \u03c3^2 l\u00e0 ph\u01b0\u01a1ng sai \u03a3 l\u00e0 k\u00fd hi\u1ec7u t\u1ed5ng h\u1ee3p, t\u1ee9c l\u00e0 t\u00ednh t\u1ed5ng c\u1ee7a t\u1ea5t c\u1ea3 c\u00e1c th\u00e0nh ph\u1ea7n trong ngo\u1eb7c. xi l\u00e0 t\u1eebng gi\u00e1 tr\u1ecb trong t\u1eadp d\u1eef li\u1ec7u \u03bc l\u00e0 gi\u00e1 tr\u1ecb trung b\u00ecnh c\u1ee7a t\u1eadp d\u1eef li\u1ec7u n l\u00e0 s\u1ed1 l\u01b0\u1ee3ng gi\u00e1 tr\u1ecb trong t\u1eadp d\u1eef li\u1ec7u.<\/p>\n<h3 style=\"text-align: justify;\"><span id=\"Vi_du_minh_hoa_cach_tinh_variance\">V\u00ed d\u1ee5 minh h\u1ecda c\u00e1ch t\u00ednh variance<\/span><\/h3>\n<p style=\"text-align: justify;\">Gi\u1ea3 s\u1eed ch\u00fang ta c\u00f3 t\u1eadp d\u1eef li\u1ec7u sau \u0111\u00e2y \u0111\u1ea1i di\u1ec7n cho s\u1ed1 l\u01b0\u1ee3ng s\u1ea3n ph\u1ea9m b\u00e1n ra h\u00e0ng th\u00e1ng trong 6 th\u00e1ng li\u00ean ti\u1ebfp: 50, 60, 45, 55, 65, 50.<\/p>\n<ul>\n<li aria-level=\"1\">B\u01b0\u1edbc 1: T\u00ednh gi\u00e1 tr\u1ecb trung b\u00ecnh (\u03bc): \u03bc = (50 + 60 + 45 + 55 + 65 + 50) \/ 6 = 51.67<\/li>\n<li aria-level=\"1\">B\u01b0\u1edbc 2: T\u00ednh b\u00ecnh ph\u01b0\u01a1ng c\u1ee7a \u0111\u1ed9 sai l\u1ec7ch c\u1ee7a t\u1eebng gi\u00e1 tr\u1ecb so v\u1edbi gi\u00e1 tr\u1ecb trung b\u00ecnh: (50 &#8211; 51.67)^2 \u2248 2.78 (60 &#8211; 51.67)^2 \u2248 70.22 (45 &#8211; 51.67)^2 \u2248 44.56 (55 &#8211; 51.67)^2 \u2248 11.22 (65 &#8211; 51.67)^2 \u2248 179.78 (50 &#8211; 51.67)^2 \u2248 2.78<\/li>\n<li aria-level=\"1\">B\u01b0\u1edbc 3: T\u00ednh t\u1ed5ng h\u1ee3p c\u00e1c b\u00ecnh ph\u01b0\u01a1ng sai l\u1ec7ch v\u00e0 chia cho s\u1ed1 l\u01b0\u1ee3ng gi\u00e1 tr\u1ecb trong t\u1eadp d\u1eef li\u1ec7u (n): \u03c3^2 = (2.78 + 70.22 + 44.56 + 11.22 + 179.78 + 2.78) \/ 6 \u2248 54.11<\/li>\n<li style=\"text-align: justify;\">Variance c\u1ee7a t\u1eadp d\u1eef li\u1ec7u l\u00e0 kho\u1ea3ng 54.11.<\/li>\n<\/ul>\n<p style=\"text-align: justify;\">\u0110\u00e2y l\u00e0 c\u00e1ch t\u00ednh to\u00e1n ph\u01b0\u01a1ng sai t\u1eeb t\u1eadp d\u1eef li\u1ec7u cho tr\u01b0\u1edbc. Ph\u01b0\u01a1ng sai gi\u00fap ch\u00fang ta hi\u1ec3u r\u00f5 h\u01a1n v\u1ec1 s\u1ef1 bi\u1ebfn \u0111\u1ed5i v\u00e0 ph\u00e2n t\u00e1n c\u1ee7a d\u1eef li\u1ec7u, t\u1eeb \u0111\u00f3 th\u1ef1c hi\u1ec7n c\u00e1c ph\u00e2n t\u00edch v\u00e0 quy\u1ebft \u0111\u1ecbnh hi\u1ec7u qu\u1ea3 trong l\u0129nh v\u1ef1c th\u1ed1ng k\u00ea v\u00e0 t\u00e0i ch\u00ednh.<\/p>\n<blockquote><p>Xem th\u00eam: <a href=\"https:\/\/tuyendung.edu.vn\/blog\/quy-luat-kinh-te-la-gi.html\" target=\"_blank\" rel=\"noopener\"><strong>Quy lu\u1eadt kinh t\u1ebf l\u00e0 g\u00ec? T\u00ecm hi\u1ec3u kh\u00e1i ni\u1ec7m c\u01a1 b\u1ea3n v\u00e0 \u00fd ngh\u0129a<\/strong><\/a><\/p><\/blockquote>\n<h2 style=\"text-align: justify;\"><span id=\"Ung_dung_cua_variance\">\u1ee8ng d\u1ee5ng c\u1ee7a variance<\/span><\/h2>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-791\" src=\"https:\/\/tuyendung.edu.vn\/blog\/wp-content\/uploads\/2023\/07\/22\/cach-tinh-Variance.png\" alt=\"\" width=\"800\" height=\"600\" srcset=\"https:\/\/tuyendung.edu.vn\/blog\/wp-content\/uploads\/2023\/07\/22\/cach-tinh-Variance-768x576.png 768w, https:\/\/tuyendung.edu.vn\/blog\/wp-content\/uploads\/2023\/07\/22\/cach-tinh-Variance.png 800w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><\/p>\n<h3 style=\"text-align: justify;\"><span id=\"Variance_trong_thong_ke\">Variance trong th\u1ed1ng k\u00ea<\/span><\/h3>\n<ul style=\"text-align: justify;\">\n<li aria-level=\"1\">\u0110\u00e1nh gi\u00e1 s\u1ef1 ph\u00e2n t\u00e1n v\u00e0 bi\u1ebfn \u0111\u1ed5i d\u1eef li\u1ec7u: Variance gi\u00fap \u0111o l\u01b0\u1eddng m\u1ee9c \u0111\u1ed9 ph\u00e2n t\u00e1n v\u00e0 bi\u1ebfn \u0111\u1ed5i c\u1ee7a d\u1eef li\u1ec7u trong m\u1ed9t t\u1eadp h\u1ee3p. Khi ph\u01b0\u01a1ng sai l\u1edbn, c\u00f3 ngh\u0129a l\u00e0 d\u1eef li\u1ec7u c\u00f3 s\u1ef1 bi\u1ebfn \u0111\u1ed5i m\u1ea1nh, trong khi ph\u01b0\u01a1ng sai nh\u1ecf h\u01a1n th\u1ec3 hi\u1ec7n d\u1eef li\u1ec7u t\u1eadp trung v\u00e0 \u1ed5n \u0111\u1ecbnh h\u01a1n. \u0110i\u1ec1u n\u00e0y gi\u00fap nh\u1eadn di\u1ec7n c\u00e1c xu h\u01b0\u1edbng, bi\u1ebfn \u0111\u1ed5i v\u00e0 kh\u1ea3 n\u0103ng d\u1ef1 \u0111o\u00e1n k\u1ebft qu\u1ea3 c\u1ee7a d\u1eef li\u1ec7u.<\/li>\n<li aria-level=\"1\">\u01af\u1edbc l\u01b0\u1ee3ng sai s\u1ed1 v\u00e0 \u0111\u1ed9 tin c\u1eady c\u1ee7a m\u1eabu: Variance l\u00e0 m\u1ed9t trong c\u00e1c th\u00e0nh ph\u1ea7n quan tr\u1ecdng trong vi\u1ec7c \u01b0\u1edbc l\u01b0\u1ee3ng sai s\u1ed1 v\u00e0 \u0111\u1ed9 tin c\u1eady c\u1ee7a m\u1eabu. N\u00f3 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng trong c\u00e1c ph\u01b0\u01a1ng ph\u00e1p th\u1ed1ng k\u00ea \u0111\u1ec3 \u0111o l\u01b0\u1eddng s\u1ef1 bi\u1ebfn \u0111\u1ed5i gi\u1eefa c\u00e1c m\u1eabu, t\u1eeb \u0111\u00f3 x\u00e1c \u0111\u1ecbnh m\u1ee9c \u0111\u1ed9 ch\u00ednh x\u00e1c v\u00e0 \u0111\u00e1ng tin c\u1eady c\u1ee7a k\u1ebft qu\u1ea3 th\u1ed1ng k\u00ea.<\/li>\n<\/ul>\n<h3 style=\"text-align: justify;\"><span id=\"Variance_trong_tai_chinh\">Variance trong t\u00e0i ch\u00ednh<\/span><\/h3>\n<ul style=\"text-align: justify;\">\n<li aria-level=\"1\">\u1ee8ng d\u1ee5ng trong qu\u1ea3n l\u00fd r\u1ee7i ro \u0111\u1ea7u t\u01b0: Trong l\u0129nh v\u1ef1c t\u00e0i ch\u00ednh, qu\u1ea3n l\u00fd r\u1ee7i ro l\u00e0 m\u1ed9t y\u1ebfu t\u1ed1 quan tr\u1ecdng \u0111\u1ed1i v\u1edbi c\u00e1c nh\u00e0 \u0111\u1ea7u t\u01b0. Variance \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 \u0111o l\u01b0\u1eddng r\u1ee7i ro c\u1ee7a c\u00e1c t\u00e0i s\u1ea3n t\u00e0i ch\u00ednh v\u00e0 \u0111\u00e1nh gi\u00e1 kh\u1ea3 n\u0103ng bi\u1ebfn \u0111\u1ed9ng c\u1ee7a gi\u00e1 c\u1ed5 phi\u1ebfu, ti\u1ec1n t\u1ec7, hay t\u00e0i s\u1ea3n kh\u00e1c. Vi\u1ec7c hi\u1ec3u r\u00f5 r\u1ee7i ro gi\u00fap nh\u00e0 \u0111\u1ea7u t\u01b0 \u0111\u01b0a ra c\u00e1c quy\u1ebft \u0111\u1ecbnh \u0111\u1ea7u t\u01b0 h\u1ee3p l\u00fd v\u00e0 t\u1ed1i \u01b0u h\u00f3a l\u1ee3i nhu\u1eadn.<\/li>\n<li aria-level=\"1\">\u0110\u00e1nh gi\u00e1 hi\u1ec7u qu\u1ea3 c\u00e1c chi\u1ebfn l\u01b0\u1ee3c \u0111\u1ea7u t\u01b0: C\u00e1c chi\u1ebfn l\u01b0\u1ee3c \u0111\u1ea7u t\u01b0 th\u01b0\u1eddng li\u00ean quan \u0111\u1ebfn vi\u1ec7c \u0111\u1ecbnh gi\u00e1 t\u00e0i s\u1ea3n, d\u1ef1 \u0111o\u00e1n xu h\u01b0\u1edbng th\u1ecb tr\u01b0\u1eddng v\u00e0 t\u1ed1i \u01b0u h\u00f3a l\u1ee3i nhu\u1eadn. Ph\u01b0\u01a1ng sai \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 \u0111\u00e1nh gi\u00e1 hi\u1ec7u qu\u1ea3 c\u1ee7a c\u00e1c chi\u1ebfn l\u01b0\u1ee3c n\u00e0y, t\u1eeb \u0111\u00f3 gi\u00fap nh\u00e0 \u0111\u1ea7u t\u01b0 x\u00e1c \u0111\u1ecbnh c\u00e1c k\u1ebf ho\u1ea1ch \u0111\u1ea7u t\u01b0 t\u1ed1t nh\u1ea5t v\u00e0 tr\u00e1nh nh\u1eefng r\u1ee7i ro kh\u00f4ng \u0111\u00e1ng gi\u00e1.<\/li>\n<\/ul>\n<h2 style=\"text-align: justify;\"><span id=\"So_sanh_variance_voi_cac_khai_niem_lien_quan\">So s\u00e1nh variance v\u1edbi c\u00e1c kh\u00e1i ni\u1ec7m li\u00ean quan<\/span><\/h2>\n<h3 style=\"text-align: justify;\"><span id=\"So_sanh_variance_voi_standard_deviation\">So s\u00e1nh variance v\u1edbi standard deviation<\/span><\/h3>\n<ul style=\"text-align: justify;\">\n<li aria-level=\"1\">\u0110\u1ecbnh ngh\u0129a:\n<ul>\n<li aria-level=\"2\">Variance l\u00e0 \u0111o l\u01b0\u1eddng \u0111\u1ed9 bi\u1ebfn \u0111\u1ed5i c\u1ee7a d\u1eef li\u1ec7u d\u1ef1a tr\u00ean b\u00ecnh ph\u01b0\u01a1ng sai s\u1ed1 gi\u1eefa t\u1eebng gi\u00e1 tr\u1ecb v\u00e0 gi\u00e1 tr\u1ecb trung b\u00ecnh c\u1ee7a t\u1eadp d\u1eef li\u1ec7u.<\/li>\n<li aria-level=\"2\">Standard deviation (\u0111\u1ed9 l\u1ec7ch chu\u1ea9n) l\u00e0 c\u0103n b\u1eadc hai c\u1ee7a variance, th\u1ec3 hi\u1ec7n m\u1ee9c \u0111\u1ed9 bi\u1ebfn \u0111\u1ed5i c\u1ee7a d\u1eef li\u1ec7u theo \u0111\u01a1n v\u1ecb g\u1ed1c (\u0111\u01a1n v\u1ecb \u0111o l\u01b0\u1eddng) c\u1ee7a d\u1eef li\u1ec7u.<\/li>\n<\/ul>\n<\/li>\n<li aria-level=\"1\">Bi\u1ec3u di\u1ec5n:\n<ul>\n<li aria-level=\"2\">Variance \u0111\u01b0\u1ee3c k\u00fd hi\u1ec7u b\u1eb1ng \u03c3^2.<\/li>\n<li aria-level=\"2\">Standard deviation \u0111\u01b0\u1ee3c k\u00fd hi\u1ec7u b\u1eb1ng \u03c3.<\/li>\n<\/ul>\n<\/li>\n<li aria-level=\"1\">T\u00ednh to\u00e1n:\n<ul>\n<li aria-level=\"2\">Variance \u0111\u01b0\u1ee3c t\u00ednh b\u1eb1ng c\u00e1ch t\u00ednh t\u1ed5ng b\u00ecnh ph\u01b0\u01a1ng sai s\u1ed1 c\u1ee7a t\u1eebng gi\u00e1 tr\u1ecb so v\u1edbi gi\u00e1 tr\u1ecb trung b\u00ecnh v\u00e0 chia cho s\u1ed1 l\u01b0\u1ee3ng gi\u00e1 tr\u1ecb trong t\u1eadp d\u1eef li\u1ec7u.<\/li>\n<li aria-level=\"2\">Standard deviation \u0111\u01b0\u1ee3c t\u00ednh b\u1eb1ng c\u0103n b\u1eadc hai c\u1ee7a ph\u01b0\u01a1ng sai.<\/li>\n<\/ul>\n<\/li>\n<li aria-level=\"1\">\u01afu \u0111i\u1ec3m v\u00e0 nh\u01b0\u1ee3c \u0111i\u1ec3m:\n<ul>\n<li aria-level=\"2\">Variance c\u00f3 \u01b0u \u0111i\u1ec3m l\u00e0 n\u00f3 bao g\u1ed3m t\u1ea5t c\u1ea3 c\u00e1c gi\u00e1 tr\u1ecb d\u1eef li\u1ec7u v\u00e0 \u0111o l\u01b0\u1eddng \u0111\u1ed9 bi\u1ebfn \u0111\u1ed5i m\u1ea1nh h\u01a1n. Tuy nhi\u00ean, do \u0111\u01b0\u1ee3c t\u00ednh b\u1eb1ng b\u00ecnh ph\u01b0\u01a1ng c\u1ee7a sai s\u1ed1, n\u00f3 c\u00f3 th\u1ec3 l\u00e0m t\u0103ng \u0111\u1ed9 l\u1edbn c\u1ee7a c\u00e1c gi\u00e1 tr\u1ecb v\u00e0 kh\u00f3 hi\u1ec3u trong vi\u1ec7c so s\u00e1nh gi\u1eefa c\u00e1c t\u1eadp d\u1eef li\u1ec7u kh\u00e1c nhau.<\/li>\n<li aria-level=\"2\">Standard deviation gi\u1eef nguy\u00ean \u0111\u01a1n v\u1ecb \u0111o l\u01b0\u1eddng ban \u0111\u1ea7u, gi\u00fap d\u1ec5 d\u00e0ng so s\u00e1nh \u0111\u1ed9 bi\u1ebfn \u0111\u1ed5i gi\u1eefa c\u00e1c t\u1eadp d\u1eef li\u1ec7u v\u00e0 d\u1ec5 hi\u1ec3u h\u01a1n. Nh\u01b0\u1ee3c \u0111i\u1ec3m l\u00e0 n\u00f3 kh\u00f4ng nh\u1ea5n m\u1ea1nh \u0111\u1ebfn nh\u1eefng gi\u00e1 tr\u1ecb ngo\u1ea1i lai (outliers).<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h3 style=\"text-align: justify;\"><span id=\"So_sanh_variance_va_covariance\">So s\u00e1nh variance v\u00e0 covariance<\/span><\/h3>\n<ul style=\"text-align: justify;\">\n<li aria-level=\"1\">\u0110\u1ecbnh ngh\u0129a:\n<ul>\n<li aria-level=\"2\">Ph\u01b0\u01a1ng sai l\u00e0 \u0111o l\u01b0\u1eddng m\u1ee9c \u0111\u1ed9 bi\u1ebfn \u0111\u1ed5i c\u1ee7a m\u1ed9t bi\u1ebfn \u0111\u01a1n l\u1ebb trong m\u1ed9t t\u1eadp d\u1eef li\u1ec7u.<\/li>\n<li aria-level=\"2\">Covariance l\u00e0 \u0111o l\u01b0\u1eddng m\u1ee9c \u0111\u1ed9 bi\u1ebfn \u0111\u1ed5i chung gi\u1eefa hai bi\u1ebfn trong m\u1ed9t t\u1eadp d\u1eef li\u1ec7u.<\/li>\n<\/ul>\n<\/li>\n<li aria-level=\"1\">Bi\u1ec3u di\u1ec5n:\n<ul>\n<li aria-level=\"2\">Variance \u0111\u01b0\u1ee3c k\u00fd hi\u1ec7u b\u1eb1ng \u03c3^2.<\/li>\n<li aria-level=\"2\">Covariance \u0111\u01b0\u1ee3c k\u00fd hi\u1ec7u b\u1eb1ng Cov(X, Y) ho\u1eb7c \u03c3(X, Y).<\/li>\n<\/ul>\n<\/li>\n<li aria-level=\"1\">T\u00ednh to\u00e1n:\n<ul>\n<li aria-level=\"2\">Variance t\u00ednh b\u1eb1ng c\u00e1ch t\u00ednh t\u1ed5ng b\u00ecnh ph\u01b0\u01a1ng sai s\u1ed1 c\u1ee7a t\u1eebng gi\u00e1 tr\u1ecb so v\u1edbi gi\u00e1 tr\u1ecb trung b\u00ecnh v\u00e0 chia cho s\u1ed1 l\u01b0\u1ee3ng gi\u00e1 tr\u1ecb trong t\u1eadp d\u1eef li\u1ec7u.<\/li>\n<li aria-level=\"2\">Covariance t\u00ednh b\u1eb1ng c\u00e1ch t\u00ednh t\u1ed5ng t\u00edch ch\u1ea5t c\u1ee7a \u0111\u1ed9 sai l\u1ec7ch c\u1ee7a t\u1eebng c\u1eb7p gi\u00e1 tr\u1ecb X v\u00e0 Y so v\u1edbi gi\u00e1 tr\u1ecb trung b\u00ecnh c\u1ee7a X v\u00e0 Y v\u00e0 chia cho s\u1ed1 l\u01b0\u1ee3ng gi\u00e1 tr\u1ecb trong t\u1eadp d\u1eef li\u1ec7u.<\/li>\n<\/ul>\n<\/li>\n<li aria-level=\"1\">\u00dd ngh\u0129a:\n<ul>\n<li aria-level=\"2\">Variance t\u1eadp trung v\u00e0o s\u1ef1 bi\u1ebfn \u0111\u1ed5i c\u1ee7a m\u1ed9t bi\u1ebfn \u0111\u01a1n l\u1ebb.<\/li>\n<li aria-level=\"2\">Covariance t\u1eadp trung v\u00e0o m\u1ed1i quan h\u1ec7 t\u01b0\u01a1ng quan gi\u1eefa hai bi\u1ebfn.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p style=\"text-align: justify;\">T\u00f3m l\u1ea1i, ph\u01b0\u01a1ng sai v\u00e0 standard deviation \u0111o l\u01b0\u1eddng m\u1ee9c \u0111\u1ed9 bi\u1ebfn \u0111\u1ed5i c\u1ee7a d\u1eef li\u1ec7u, nh\u01b0ng c\u00f3 \u0111i\u1ec3m kh\u00e1c nhau v\u1ec1 \u0111\u01a1n v\u1ecb \u0111o l\u01b0\u1eddng v\u00e0 c\u00e1ch t\u00ednh to\u00e1n. Trong khi \u0111\u00f3, covariance \u0111o l\u01b0\u1eddng m\u1ed1i quan h\u1ec7 t\u01b0\u01a1ng quan gi\u1eefa hai bi\u1ebfn. Vi\u1ec7c hi\u1ec3u r\u00f5 v\u00e0 s\u1eed d\u1ee5ng c\u00e1c kh\u00e1i ni\u1ec7m n\u00e0y gi\u00fap ch\u00fang ta ph\u00e2n t\u00edch d\u1eef li\u1ec7u v\u00e0 qu\u1ea3n l\u00fd r\u1ee7i ro hi\u1ec7u qu\u1ea3 trong nhi\u1ec1u l\u0129nh v\u1ef1c, t\u1eeb th\u1ed1ng k\u00ea \u0111\u1ebfn t\u00e0i ch\u00ednh.<\/p>\n<h2 style=\"text-align: justify;\"><span id=\"Nhung_thach_thuc_khi_su_dung_variance\">Nh\u1eefng th\u00e1ch th\u1ee9c khi s\u1eed d\u1ee5ng variance<\/span><\/h2>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-792\" src=\"https:\/\/tuyendung.edu.vn\/blog\/wp-content\/uploads\/2023\/07\/22\/cong-thuc-tinh-Variance.jpg\" alt=\"c\u00f4ng th\u1ee9c t\u00ednh Variance\" width=\"800\" height=\"571\" srcset=\"https:\/\/tuyendung.edu.vn\/blog\/wp-content\/uploads\/2023\/07\/22\/cong-thuc-tinh-Variance-768x548.jpg 768w, https:\/\/tuyendung.edu.vn\/blog\/wp-content\/uploads\/2023\/07\/22\/cong-thuc-tinh-Variance.jpg 800w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><\/p>\n<h3 style=\"text-align: justify;\"><span id=\"Anh_huong_cua_du_lieu_ngoai_lai_outliers_doi_voi_variance\">\u1ea2nh h\u01b0\u1edfng c\u1ee7a d\u1eef li\u1ec7u ngo\u1ea1i lai (outliers) \u0111\u1ed1i v\u1edbi variance<\/span><\/h3>\n<p style=\"text-align: justify;\">D\u1eef li\u1ec7u ngo\u1ea1i lai (outliers) l\u00e0 c\u00e1c gi\u00e1 tr\u1ecb c\u1ef1c k\u1ef3 kh\u00e1c bi\u1ec7t v\u1edbi ph\u1ea7n c\u00f2n l\u1ea1i c\u1ee7a t\u1eadp d\u1eef li\u1ec7u. Khi c\u00f3 d\u1eef li\u1ec7u ngo\u1ea1i lai trong t\u1eadp d\u1eef li\u1ec7u, ph\u01b0\u01a1ng sai c\u00f3 th\u1ec3 b\u1ecb \u1ea3nh h\u01b0\u1edfng m\u1ea1nh, d\u1eabn \u0111\u1ebfn vi\u1ec7c b\u1ecb sai l\u1ec7ch v\u00e0 kh\u00f4ng ph\u1ea3n \u00e1nh ch\u00ednh x\u00e1c m\u1ee9c \u0111\u1ed9 bi\u1ebfn \u0111\u1ed5i c\u1ee7a d\u1eef li\u1ec7u chung.<\/p>\n<p style=\"text-align: justify;\">V\u00ed d\u1ee5: Gi\u1ea3 s\u1eed ch\u00fang ta c\u00f3 t\u1eadp d\u1eef li\u1ec7u chi\u1ec1u cao c\u1ee7a m\u1ed9t nh\u00f3m ng\u01b0\u1eddi, v\u00e0 trong \u0111\u00f3 c\u00f3 m\u1ed9t ng\u01b0\u1eddi cao h\u01a1n r\u1ea5t nhi\u1ec1u so v\u1edbi nh\u1eefng ng\u01b0\u1eddi kh\u00e1c. N\u1ebfu kh\u00f4ng lo\u1ea1i b\u1ecf d\u1eef li\u1ec7u ngo\u1ea1i lai n\u00e0y, ph\u01b0\u01a1ng sai s\u1ebd cao h\u01a1n nhi\u1ec1u so v\u1edbi tr\u01b0\u1eddng h\u1ee3p lo\u1ea1i b\u1ecf, d\u1eabn \u0111\u1ebfn vi\u1ec7c \u0111\u00e1nh gi\u00e1 sai v\u1ec1 m\u1ee9c \u0111\u1ed9 bi\u1ebfn \u0111\u1ed5i c\u1ee7a chi\u1ec1u cao trong nh\u00f3m ng\u01b0\u1eddi n\u00e0y.<\/p>\n<h3 style=\"text-align: justify;\"><span id=\"Rui_ro_sai_tuong_khi_khong_hieu_ro_gia_tri_variance\">R\u1ee7i ro sai t\u01b0\u1edfng khi kh\u00f4ng hi\u1ec3u r\u00f5 gi\u00e1 tr\u1ecb variance<\/span><\/h3>\n<p style=\"text-align: justify;\">Ph\u01b0\u01a1ng sai l\u00e0 m\u1ed9t ch\u1ec9 s\u1ed1 \u0111o l\u01b0\u1eddng \u0111\u1ed9 bi\u1ebfn \u0111\u1ed5i c\u1ee7a d\u1eef li\u1ec7u v\u00e0 n\u00f3 c\u00f3 th\u1ec3 d\u1eabn \u0111\u1ebfn nh\u1eefng r\u1ee7i ro sai t\u01b0\u1edfng khi kh\u00f4ng \u0111\u01b0\u1ee3c hi\u1ec3u r\u00f5 v\u00e0 \u0111\u00e1nh gi\u00e1 ch\u00ednh x\u00e1c. M\u1ed9t s\u1ed1 r\u1ee7i ro khi s\u1eed d\u1ee5ng variance l\u00e0:<\/p>\n<ul style=\"text-align: justify;\">\n<li aria-level=\"1\">Hi\u1ec3u sai v\u1ec1 \u0111\u01a1n v\u1ecb \u0111o l\u01b0\u1eddng: Ph\u01b0\u01a1ng sai\u00a0\u0111\u01b0\u1ee3c t\u00ednh b\u1eb1ng b\u00ecnh ph\u01b0\u01a1ng c\u1ee7a sai s\u1ed1 v\u00e0 do \u0111\u00f3 c\u00f3 \u0111\u01a1n v\u1ecb \u0111o l\u01b0\u1eddng l\u00e0 b\u00ecnh ph\u01b0\u01a1ng c\u1ee7a \u0111\u01a1n v\u1ecb g\u1ed1c. Khi kh\u00f4ng nh\u1eadn ra \u0111i\u1ec1u n\u00e0y, ng\u01b0\u1eddi s\u1eed d\u1ee5ng c\u00f3 th\u1ec3 hi\u1ec3u sai v\u1ec1 m\u1ee9c \u0111\u1ed9 bi\u1ebfn \u0111\u1ed5i th\u1ef1c s\u1ef1 c\u1ee7a d\u1eef li\u1ec7u.<\/li>\n<li aria-level=\"1\">Kh\u00f4ng \u0111\u00e1nh gi\u00e1 c\u1ea9n th\u1eadn c\u00e1c gi\u00e1 tr\u1ecb ngo\u1ea1i lai: Nh\u01b0 \u0111\u00e3 \u0111\u1ec1 c\u1eadp \u1edf tr\u00ean, d\u1eef li\u1ec7u ngo\u1ea1i lai c\u00f3 th\u1ec3 \u1ea3nh h\u01b0\u1edfng m\u1ea1nh \u0111\u1ebfn variance. N\u1ebfu kh\u00f4ng x\u1eed l\u00fd ho\u1eb7c lo\u1ea1i b\u1ecf c\u00e1c gi\u00e1 tr\u1ecb ngo\u1ea1i lai m\u1ed9t c\u00e1ch th\u00edch h\u1ee3p, k\u1ebft qu\u1ea3 t\u1eeb variance c\u00f3 th\u1ec3 b\u1ecb sai l\u1ec7ch v\u00e0 kh\u00f4ng ph\u1ea3n \u00e1nh \u0111\u00fang t\u00ednh ch\u1ea5t c\u1ee7a t\u1eadp d\u1eef li\u1ec7u.<\/li>\n<li aria-level=\"1\">S\u1eed d\u1ee5ng kh\u00f4ng \u0111\u00fang trong tr\u01b0\u1eddng h\u1ee3p d\u1eef li\u1ec7u kh\u00f4ng \u0111\u1ed3ng nh\u1ea5t: Ph\u01b0\u01a1ng sai l\u00e0 m\u1ed9t ph\u01b0\u01a1ng ph\u00e1p \u0111o l\u01b0\u1eddng d\u1ef1a tr\u00ean gi\u1ea3 \u0111\u1ecbnh r\u1eb1ng d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c ph\u00e2n ph\u1ed1i \u0111\u1ed3ng nh\u1ea5t v\u00e0 c\u00f3 t\u00ednh ch\u1ea5t ng\u1eabu nhi\u00ean. Trong tr\u01b0\u1eddng h\u1ee3p d\u1eef li\u1ec7u kh\u00f4ng \u0111\u1ed3ng nh\u1ea5t ho\u1eb7c kh\u00f4ng tu\u00e2n theo ph\u00e2n ph\u1ed1i chu\u1ea9n, vi\u1ec7c s\u1eed d\u1ee5ng variance c\u00f3 th\u1ec3 kh\u00f4ng \u0111\u01b0a ra k\u1ebft qu\u1ea3 ch\u00ednh x\u00e1c v\u00e0 \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn \u0111\u1ed9 tin c\u1eady c\u1ee7a ph\u00e2n t\u00edch.<\/li>\n<\/ul>\n<p style=\"text-align: justify;\">\u0110\u1ec3 tr\u00e1nh nh\u1eefng th\u00e1ch th\u1ee9c v\u00e0 r\u1ee7i ro khi s\u1eed d\u1ee5ng ph\u01b0\u01a1ng sai, ng\u01b0\u1eddi s\u1eed d\u1ee5ng c\u1ea7n hi\u1ec3u r\u00f5 v\u1ec1 c\u00e1c gi\u1ea3 \u0111\u1ecbnh, gi\u00e1 tr\u1ecb \u0111o l\u01b0\u1eddng, v\u00e0 t\u00ednh ch\u1ea5t c\u1ee7a d\u1eef li\u1ec7u. \u0110\u1ed3ng th\u1eddi, vi\u1ec7c x\u1eed l\u00fd c\u00e1c gi\u00e1 tr\u1ecb ngo\u1ea1i lai v\u00e0 ki\u1ec3m tra t\u00ednh \u0111\u1ed3ng nh\u1ea5t c\u1ee7a d\u1eef li\u1ec7u s\u1ebd gi\u00fap \u0111\u1ea3m b\u1ea3o t\u00ednh ch\u00ednh x\u00e1c v\u00e0 hi\u1ec7u qu\u1ea3 khi s\u1eed d\u1ee5ng variance trong ph\u00e2n t\u00edch v\u00e0 quy\u1ebft \u0111\u1ecbnh.<\/p>\n<blockquote><p>Xem th\u00eam: <a href=\"https:\/\/tuyendung.edu.vn\/blog\/wacc-la-gi.html\" target=\"_blank\" rel=\"noopener\"><strong>WACC l\u00e0 gi\u00b7: Kh\u00e1i ni\u1ec7m c\u01a1 b\u1ea3n v\u00e0 t\u00e1c \u0111\u1ed9ng \u0111\u1ebfn quy\u1ebft \u0111\u1ecbnh t\u00e0i ch\u00ednh<\/strong><\/a><\/p><\/blockquote>\n<p style=\"text-align: justify;\">Nh\u01b0 v\u1eady, ch\u00fang ta \u0111\u00e3 c\u00f9ng t\u00ecm hi\u1ec3u <a href=\"https:\/\/tuyendung.edu.vn\/blog\/variance-la-gi.html\" target=\"_blank\" rel=\"noopener\"><strong>variance l\u00e0 g\u00ec<\/strong><\/a>, ch\u1ec9 s\u1ed1 ph\u01b0\u01a1ng sai l\u00e0 m\u1ed9t kh\u00e1i ni\u1ec7m quan tr\u1ecdng trong th\u1ed1ng k\u00ea v\u00e0 t\u00e0i ch\u00ednh, gi\u00fap \u0111o l\u01b0\u1eddng m\u1ee9c \u0111\u1ed9 bi\u1ebfn \u0111\u1ed5i c\u1ee7a d\u1eef li\u1ec7u trong m\u1ed9t t\u1eadp h\u1ee3p. Vi\u1ec7c hi\u1ec3u r\u00f5 v\u00e0 \u1ee9ng d\u1ee5ng ph\u01b0\u01a1ng sai m\u1ed9t c\u00e1ch h\u1ee3p l\u00fd trong c\u00e1c ph\u00e2n t\u00edch v\u00e0 quy\u1ebft \u0111\u1ecbnh kinh doanh l\u00e0 m\u1ed9t y\u1ebfu t\u1ed1 quan tr\u1ecdng \u0111\u1ec3 \u0111\u1ea1t \u0111\u01b0\u1ee3c hi\u1ec7u qu\u1ea3 v\u00e0 th\u00e0nh c\u00f4ng trong l\u0129nh v\u1ef1c n\u00e0y. H\u1eb9n g\u1eb7p l\u1ea1i c\u00e1c b\u1ea1n trong c\u00e1c b\u00e0i vi\u1ebft ti\u1ebfp theo c\u1ee7a <strong>g\u00f3c ngh\u1ec1 nghi\u1ec7p<\/strong> nh\u00e9!<\/p>\n","protected":false},"excerpt":{"rendered":"<p>M\u1ee5c l\u1ee5c1 Variance l\u00e0 g\u00ec?1.1 \u0110\u1ecbnh ngh\u0129a variance1.2 \u00dd ngh\u0129a v\u00e0 vai tr\u00f2 c\u1ee7a variance trong th\u1ed1ng k\u00ea v\u00e0 t\u00e0i ch\u00ednh2 C\u00e1ch t\u00ednh to\u00e1n variance2.1 C\u00f4ng th\u1ee9c t\u00ednh to\u00e1n variance2.2 V\u00ed d\u1ee5 minh h\u1ecda c\u00e1ch t\u00ednh variance3 \u1ee8ng d\u1ee5ng c\u1ee7a variance3.1 Variance trong th\u1ed1ng k\u00ea3.2 Variance trong t\u00e0i ch\u00ednh4 So s\u00e1nh variance v\u1edbi c\u00e1c kh\u00e1i [&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":789,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"class_list":["post-788","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-cam-nang-doanh-nghiep"],"acf":[],"_links":{"self":[{"href":"https:\/\/tuyendung.edu.vn\/blog\/wp-json\/wp\/v2\/posts\/788","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/tuyendung.edu.vn\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/tuyendung.edu.vn\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/tuyendung.edu.vn\/blog\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/tuyendung.edu.vn\/blog\/wp-json\/wp\/v2\/comments?post=788"}],"version-history":[{"count":3,"href":"https:\/\/tuyendung.edu.vn\/blog\/wp-json\/wp\/v2\/posts\/788\/revisions"}],"predecessor-version":[{"id":796,"href":"https:\/\/tuyendung.edu.vn\/blog\/wp-json\/wp\/v2\/posts\/788\/revisions\/796"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/tuyendung.edu.vn\/blog\/wp-json\/wp\/v2\/media\/789"}],"wp:attachment":[{"href":"https:\/\/tuyendung.edu.vn\/blog\/wp-json\/wp\/v2\/media?parent=788"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/tuyendung.edu.vn\/blog\/wp-json\/wp\/v2\/categories?post=788"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}