Question

某廠生產(chǎn)電子元件,其產(chǎn)品的次品率為5%,現(xiàn)從一批產(chǎn)品中任意地連續(xù)取出2件,其中次品數(shù)X的概率分布是

X	0	1	2
P

Answer 1

解析：由題意“任意地連續(xù)取出2件”可認(rèn)為兩次獨(dú)立重復(fù)試驗(yàn),則次品數(shù)X服從二項(xiàng)分布,即X—(2,0.05),

∴X=0時(shí),P₀=C⁰₂(0.95)²=0.902 5;

X=1時(shí),P₁=C0.95×0.05=0.095;

X=2時(shí),P₂=C0.05²=0.002 5.

則X的概率分布為:

X	0	1	2
P	0.902 5	0.095	0.002 5

答案：0.902 5 0.095 0.002 5