x拔是什么x拔 X拔是啥意思
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平均数符号X拔，X有上划线，
绛旓細璇烩淴鎷斺濓紝鎰忔濇槸骞冲潎鏁銆
绛旓細鎷斾竴鑸湴锛屽浜巒涓暟x1锛寈2锛屸︼紝xn锛鎴戜滑鎶婂彨鍋氳繖n涓暟鐨勭畻鏈钩鍧囨暟锛坢ean锛宎verage锛夛紝绠绉板钩鍧囨暟锛岃涓猴紝璇讳綔鈥渪鎷斻備竴鑸湴锛屽浜巒涓暟x1锛寈2锛屸︼紝xn锛屾垜浠妸 鍙仛杩檔涓暟鐨勭畻鏈钩鍧囨暟锛坢ean锛宎verage锛夛紝绠绉板钩鍧囨暟锛岃涓 锛岃浣溾渪鎷旓紙鎷斿嵆bar锛夆濄
绛旓細x鎷=瀛︾敓鐨勬诲垎锛堝嵆x.f锛/瀛︾敓鎬讳汉鏁(鍗砯)銆X鎷旇〃绀烘牱鏈Xi锛坕=1锛2锛屸︼紝n锛夌殑鍧囧硷紝绠璁颁负X'銆傗埖X~N锛0锛1锛夛紝鈭碭'~N锛0锛1/n锛夈傗埓E锛圶'²锛=D锛圶'锛=1/n銆俋'鐨勫瘑搴﹀嚱鏁癴锛坸'锛=Ae^锛-nx²/2锛斤紝x'鈭圧锛孉=鈭氾蓟n/锛2蟺锛夛冀銆傗埓E锛坸'^4锛=鈭紙-鈭...
绛旓細姝ｆ佸垎甯冪殑x鎷旓細缁熻閲忓氨鏄疿鎷=15.5瀵瑰簲鍦ㄦ爣鍑嗘鎬佸垎甯冪殑涓涓噺銆傚嵆瀵瑰簲鐨勫间负m=锛圶鎷-鍧囧硷級/鏍锋湰鏍囧噯宸傚叾涓牱鏈爣鍑嗗樊=鎬讳綋鏍囧噯宸/鏍锋湰鎬婚噺鐨勫紑浜屾鏂广X鎷旇〃绀烘牱鏈Xi锛坕=1锛2锛屸︼紝n锛夌殑鍧囧硷紝绠璁颁负X'銆傗埖X~N锛0锛1锛夛紝鈭碭'~N锛0锛1/n锛夈傗埓E锛圶'²锛=D锛圶'锛=1...
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绛旓細姝ｆ佸垎甯冧腑x鎷绛変簬鏈熸湜銆侲(X)琛ㄧず闅忔満鍙橀噺鐨勫钩鍧囨按骞筹紝涔熷彨鏈熸湜锛岃X鎷琛ㄧず鐨勬槸涓缁勬暟鎹殑骞冲潎鍊硷紝灏辨槸鎵鏈夌殑鏁板姞璧锋潵鍐嶉櫎浠ヤ釜鏁帮紝瀹冨拰E(X)鐨勫尯鍒槸闅忔満鍙橀噺鍙栧兼槸鍜屾鐜囨湁鍏崇郴鐨勩侲(X1)=E(X2)=E(X3)=E(Xn)=0
绛旓細x鎷旀槸骞冲潎鏁鐨勬剰鎬濓紝涓涓暟鎹簲璇ヤ笉浼氭湁鏂瑰樊锛屼絾涓缁勬暟鎹細鏈夋柟宸
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