请教一道方差计算题
问题描述:
请教一道方差计算题
(-22%-17.4%)^2×0.1+(-2%-17.4%)^2×0.2+(20%-17.4%)^2×0.4+(35%-17.4%)^2×0.2+(50%-17.4%)^2×0.1=多少,麻烦列出计算过程,
答
(-22%-17.4%)^2×0.1+(-2%-17.4%)^2×0.2+(20%-17.4%)^2×0.4+(35%-17.4%)^2×0.2+(50%-17.4%)^2×0.1=(-0.394)^2×0.1+(-0.194)^2×0.2+0.026^2×0.4+0.176^2×0.2+0.326^2×0.1=0.155236+0.0075272+0.00027...