mean and standard deviation

Question

a)	61.5 and 3.33
b)	13.5 and 3.33
c)	13.5 and 11.07
d)	61.5 and 13.5

1. A consumer research company reported that 18% of new cars of a certain model will require repairs during the warranty period. A particular dealership sells 75 such cars last month. The mean and standard deviation of the number that will NOT require repairs during the warranty period are

Answer 1

Answer b.

Mean=0.18×75=13.5.

SD=√(13.5(1-0.18))=3.33 approx.

Binomial distribution.