Question

According to a college survey, 22% of all students work full time. find the mean for the number of 3) students who work full time in samples of size 16.

Answer 1

Assuming that the students worldwide are being considered, because of the extremely large population, this can be considered as a binomial distribution. A normal distribution is used most usually as a fair approximation of the binomial. The mean is the expectation, therefore:
E[x] = np = (16)(0.22) = 3.52 
μ = 3.52