A.μ-1.645σ B.μ-1.96σ C.μ+1.96σ D.μ+1.645σ
A.nπ和n(1-π)均大于等于5 B.nπ或n(1-π)大于等于5 C.nπ足夠大 D.π足夠大
A.P(X≥k) B.P(X≥k+1) C.P(X≤k) D.P(X≤k-1)