Question

a.) If a student randomly guesses at 20 multiple-choice questions, find the probability that the student gets exactly four correct. Each question has four possible choices.

0.190

0.162

0.085

0.218

b.) 80% of members of a club consume alcoholic beverage. Of 14 members are randomly selected what is the probability that all of them drinks alcohol beverage?

0.044

0

1

0.8

c.) A school is sending 12 children to a camp. If 20% of the children in the school are first graders, and the 12 children are selected at random from among all 6 grades at the school, find the mean and variance of the number of first graders chosen?

d.) At a particular hospital, 40% of staff are nurse assistants. If 12 staff members are randomly selected, what is the probability that exactly 4 are nurse assistants?

Answer 1