Question 1008087
it is 8C5(0.25)^5(0.75)^3=0.0231
For at least 6, we need 6,7,8
6: 8C6(0.25^6)(0.75^2)=0.0038
7: 8(0.25^7)*0.75=0.0008
for 8, 0.25^8=0.00002
The probability is 0.0046.
The expected value is 2 with the variance 1.5.