卓娅 · 2021年11月24日
NO.PZ2015120604000066
问题如下：
Determine the variance of a discrete uniform distribution, which is defined as X={2,4,6,8,10}.
选项：
A.6.
B.8.
C.2.8.
解释：
B is correct
Expected value= (1/5)(2+4+6+8+10) = 6
Variance= (1/5)[(2-6)2 + (4-6)2+ (6-6)2 + (8-6)2+(10-6)2] = 8
离散分布计算方差的逻辑是什么哦？
NO.PZ2015120604000066 问题如下 termine the varianof a screte uniform stribution, whiis fineX={2,4,6,8,10}. A.6. B.8. C.2.8. B is correctExpectevalue= (1/5)(2+4+6+8+10) = 6Variance= (1/5)[(2-6)2 + (4-6)2+ (6-6)2 + (8-6)2+(10-6)2] = 8 分母为什么不是n-1?
NO.PZ2015120604000066 问题如下 termine the varianof a screte uniform stribution, whiis fineX={2,4,6,8,10}. A.6. B.8. C.2.8. B is correctExpectevalue= (1/5)(2+4+6+8+10) = 6Variance= (1/5)[(2-6)2 + (4-6)2+ (6-6)2 + (8-6)2+(10-6)2] = 8 写的是离散标准啊
NO.PZ2015120604000066问题如下termine the varianof a screte uniform stribution, whiis fineX={2,4,6,8,10}.A.6.B.8.C.2.8.B is correctExpectevalue= (1/5)(2+4+6+8+10) = 6Variance= (1/5)[(2-6)2 + (4-6)2+ (6-6)2 + (8-6)2+(10-6)2] = 8用计算器就可以算了，是之前的题目，请问和本章的关系是什么
NO.PZ2015120604000066 我这么算出来对的答案 但逻辑是 方差= 1/5（1-0.2）^2
