The local swim team is considering offering a new semi-private class aimed at entry-level swimmers, but needs a minimum number of swimmers to sign up in order to be cost effective. last year’s data showed that during 8 swim sessions the average number of entry-level swimmers attending was 15. suppose the instructor wants to conduct a hypothesis test and the alternative hypothesis is "the population mean is greater than 15" if the sample size is 5, σ is known, and alpha = .01, the critical value of z isa) 2.575b) -2.575c) 2.33d) -2.33e) 2.45