In the most recent election, 19 percent of all eligible college students voted. If a random sample of 20 students were surveyed, find the probability that exactly half voted in the election.

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