這道題應(yīng)該用二項(xiàng)分布或泊松分布做.我全用的二項(xiàng).
A.1人負(fù)責(zé)20臺(tái),出現(xiàn)維修不及的概率
b~(20,0.01)
P{X>1}=1-P{X=0}-P{X=1}=1.68%
5組人員中出現(xiàn)維修不及的概率
b~(5,0.0168)
P{X>=1}=1-P{X=0}=8.15%
B.3人負(fù)責(zé)一百臺(tái)
b~(100,0.01)
P{X>3}=1-P{X=0}-P{X=1}-P{X=2}-P{X=3}=1.83%
我算出來的結(jié)果也未必準(zhǔn)確,你自己算下吧