A small school with 60 total students records how many of their students attend school on each of the 180 days in a school year. The mean number of students in attendance daily is 55 students and the standard deviation is 4 students. Suppose that we take random samples of 55 school days and calculate the mean number of students \bar x x ˉ x, with, \bar, on top in attendance on those days in each sample.

the revenue of the fitness center, y, is the product of two factors: the number of members and the fee paid by each member. there are 320 members now, but number of members goes down by 10 for each $5 increase in fees, so if x is the number of $5 price increases then members is equal to (320 - 10x). since the fee is currently $45, and the fee increases by $5 for every price bump x, the fee is given by (45 + 5x). so, revenue y is given by y = (320 - 10x)(45 + 5x).