这个方差怎么算X2023P0.20.160.2023.512
<p>问题：这个方差怎么算X2023P0.20.160.2023.512<p>答案：↓↓↓<p class="nav-title mt10" style="border-top:1px solid #ccc;padding-top: 10px;">陈康的回答：<div class="content-b">网友采纳 先计算加权平均数X'=（0×0.2+1×0.16+2×0.128+4×0.512）÷（0.2+0.16+0.128+0.512）=2.464再计算方差D=0.2×(2.464-0)^2+0.16×(2.464-1)^2+0.128×(2.464-2)^2+0.512×(2.464-4)^2=2.7927顺便求下标准差...
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