Then ξ 1 ~ b (1, 1/5), ξ 2 ~ b (2, 1/5)
P(ξ 1=0)=4/5,P(ξ 1= 1)= 1/5
P(ξ2=0)= 16/25,P(ξ2= 1)=8/25,P(ξ2=2)= 1/25
ξ=ξ 1+ξ2
P(ξ=0)=64/ 125,P(ξ= 1)=48/ 125,P(ξ=2)= 12/ 125,P(ξ=0)= 1/ 125
Bachelor of Religion Education bachelor of religious education
ξ 0 1 2 3
p 64/ 125 48/ 125 12/ 125 1/ 125
eξ= eξ 1+eξ2 = 1 *( 1/5)+2 *( 1/5)= 3/5
(This question requires the second bag to touch two balls, Eξ2≠2/5)
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