A.設(shè)備誤差 B.環(huán)境誤差 C.人員誤差 D.方法誤差
A.P(x1≤ξ≤x2)=F(x2)-F(x1) B.(-x)=1-Φ(x) C.P(AB)=P(A)P(B) D.P(A+B)=P(A)+P(B)
A.當(dāng)σ已知時(shí)較窄 B.當(dāng)σ已知時(shí)較寬 C.當(dāng)σ已知時(shí),用s作估計(jì)時(shí)較寬 D.當(dāng)σ未知時(shí),用s作估計(jì)時(shí)較窄