Answer:. This would be 0.81^20 for none of the 19=0.0148
Step-by-step explanation:With a tree diagram, there are two possibilities, one is ND from 1 D from 2, with probability (5/8)(2/5)=(1/4) and the other is (3/8)(3/5)=9/40 That would be 19/40 for the answer.
3. Poisson parameter lambda=5
for P(0), it is e^(-5)(5^0)/0! or e^(-5)=0.0067
for P(1), it is e^(-5)(5^1)/1! or 5e(-5)
The total probability is 6e^-5 or 0.0404
4. the mean is 1000 hours, so lambda is the reciprocal or 1/1000
the probability it will last <800 hours is 1-e^(-800*1/1000) or 1-e^(-.8)=0.5507
5. assume p=0.4 since it ca't be 4
sd is sqrt (np*(1-p))=sqrt (6*0.6=sqrt(3.6)=1.90
