Set 4 (5) .DOCX Tools Help Normal text Helvet... - 11.5 + BIUA o + C ||| 19. (4 points) 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 Population mean ()= 2.50 Population standard deviation ( ) = unknown Commuter Students Sample mean (X)= 2.78 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 (a) 0.05 (the question asks us to test the hypothesis at 0.05 significance level). 3. Z-critical= Format Tools Help Normal text Calibri - 12 +BIU A G + 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: Z= X-M SVN-1 Step 4: Make a Decision and Interpret the Test Results. | Page 6 of 7