18) According to a survey, 67% of the students at Delta own a calculator. A group of 9 students is randomly selected, what is the probability that exactly 7 students own a calculator? (Hint: B D)

A.0.007

B.0.157

C.0.238

D.0.372

19)The final exam is worth 200 points with the usual 10% grading scale. Assume that the final exam scores are normally distributed with the mean of 157 points and the standard deviation of 26. If 77 students were taken the final exam, approximately how many students earned a B on the final exam? (Hint: N D)

A.62

B.42

C.21

D.20

20) According to a survey, the average height of NBA players is 78 in. with a standard deviation of 7 in., find the probability that a group of 36 randomly selected NBA players will have an average height TALLER than 81 in. (Hint: CLT)

A.0.0051

B.0.3336

C.0.6664

D.0.9949