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(duì)稱軸的面積為90% B.μ-1.96σ到曲線對(duì)稱軸的面積為10% C.μ-1.96σ到曲線對(duì)稱軸的面積為5% D.μ-1.96σ到曲線對(duì)稱軸的面積為45% E.μ-1.96σ到曲線對(duì)稱軸的面積為47.5%
A.當(dāng)σ不變時(shí),隨著μ增大,曲線向右移 B.當(dāng)σ不變時(shí),隨著μ增大,曲線向左移 C.當(dāng)μ不變時(shí),隨著σ增大,曲線向右移 D.當(dāng)μ不變時(shí),隨著σ增大,曲線將沒有變化 E.以上說法均不正確