The local swim team is considering offering a new semi-private class aimed an entry-level swimmers, but needs at 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. The alternative hypothesis for this hypothesis test is: "the population mean is less than 15". The sample size is 8, is known, and = .05, the critical value ofzis _______.

2.05

1.96

-1.645

1.645

-1.96