令 Z=min{X1,X2,…,Xn} Fz()=1-P(X1>,X2>,,Xn>z) =1-P(X1>z)P(X2>z)…P(Xm>z) e1-i0-X,≤0 0 z<0 z<0 1-e z≥0 fz(z)=了n nz z≥0 即 Z-E E=号 E(nZ)=0 故nZ是0的无偏估计量. min{ , , , } 令 Z = X1 X2  Xn      ≥ < = − 0 0 0 ( ) e z n z f z nz Z θ θ 即 n E Z n Z E θ θ  =      ~ ( )     − ≥ < = − 1 0 0 0 e z z nz θ E(nZ) = θ 故 nZ 是θ 的无偏估计量. 1 ( ) ( ) ( ) 1 2 P X z P X z P X z = − > >  n > ∏ = = − − ≤ n i i P X z 1 1 (1 ( )) ( ) 1 ( , , , ) 1 2 F z P X z X z X z Z = − > >  n >