未分类题

设塑料的抗压强度近似服从正态分布,且相互独立.现有两种塑料,已知方差==1.分别取容量为n1=10与n2=8的样本,测得样本均值=162.5,=155.0.求均值差μ12的置信区间.(α=0.05)

A.现有两种塑料,已知方差B.174.24.96:6088/Latex/latex.action?latex=XHNpZ21hIF97MX1eezJ9'
C.174.24.96:6088/Latex/latex.action?latex=XHNpZ21hIF97Mn1eezJ9'
D.分别取容量为n1=10与n2=8的样本,测得样本均值E.174.24.96:6088/Latex/latex.action?latex=XGJhcnt4fQ%3D%3D'
F.5,G.174.24.96:6088/Latex/latex.action?latex=XGJhcnt5fQ%3D%3D'
H.0.求均值差μ12

【参考答案】

(6.57,8.43).