1. A researcher wonders whether commuter students are different from the general student body in terms of academic achievement. She has gathered the following information. Test at 0.05 significance level.

Student body	Commuter Students
Population mean ()= 2.50	Sample mean ()= 2.78
Population standard deviation ()= unknown	Sample standard deviation (s) = 1.23
	Sample size (N)= 122

Step 1: To answer this question, the first thing that we need to do is to formulate the research and null hypotheses. State the research and null hypotheses below:

H1 (Research hypothesis):

Ho (Null hypothesis):

Step 2: Select Sampling Distribution and Establish the Critical Region

1. Sampling Distribution= Z-distribution
2. Alpha () = 0.05 (the question asks us to test the hypothesis at 0.05 significance level).
3. Z-critical=

• Look up the normal curve table (=Z-table) in Appendix A of the textbook and see what the Critical-Z value is in this case.

Step 3: Compute the Test Statistic

Use the following formula and compute the test statistic (=Calculated Z=Z-obtained). Round off your answer to the nearest two decimal places.

Formula:

Step 4: Make a Decision and Interpret the Test Results.