The probabilities that a batch of 4 computers will contain 0,1,2,3,and 4 defective computers are 0.4096,0.4096,0.1536,0.0256,and 0.0016,respectively.Find the expected number of defective computers in a batch of 4.
A)0.80
B)0.89
C)1.21
D)0.70
E)2.00

Question

Quizplus · Accepted Answer

The expected number of defective computers is calculated by multiplying each outcome by its probability and summing these products: $0*0.4096 + 1*0.4096 + 2*0.1536 + 3*0.0256 + 4*0.0016 = 0 + 0.4096 + 0.3072 + 0.0768 + 0.0064 = 0.8$.

The Probabilities That a Batch of 4 Computers Will Contain