Someone claims that firstyear students in New Jersey public

Someone claims that first-year students in New Jersey public universities are as tall on average as first-year students in Pennsylvania public universities. To test that claim, you collect samples of 100 students from each of the two states and obtain the following results: The mean height for New Jersey students is 65 inches and the mean height for Pennsylvania students is 64 inches. Assume that population standard deviations are known and are 8 inches for both New Jersey and Pennsylvania. Using a significance level of 0.05, what is/are the critical value(s)?

There are two critical values. They are -2.58 and +2.58.

There is only one critical value. It is +2.58.

There is only one critical value. It is +1.96.

There are two critical values. They are -1.96 and +1.96.

Solution

There are two critical values. They are -1.96 and +1.96. is the answer as it is two tailed.