var和d 概率論var和d 計(jì)量經(jīng)濟(jì)學(xué)中什么叫“mean dependent var和S.D. dependent var”?D(X)與E(X)括號(hào)里面是怎么計(jì)算的?D(x)是方差,e(x)是期望... 2021-03-10 3189次瀏覽