A.68.27% B.90% C.95% D.99% E.45%
A.-∞到+1.96 B.-1.96到+1.96 C.-∞到+2.58 D.-2.58到+2.58 E.-1.64到+1.64
A.μ-1.96σ到曲線對稱軸的面積為90% B.μ-1.96σ到曲線對稱軸的面積為10% C.μ-1.96σ到曲線對稱軸的面積為5% D.μ-1.96σ到曲線對稱軸的面積為45% E.μ-1.96σ到曲線對稱軸的面積為47.5%