16. A researcher in health psychology wants to know whether exercise affects mood in teenagers. She takes a sample of 30 teenagers and measures their mood before they run 1 km and then measures their mood again after the run. Use the following summary statistics to answer the questions: Mood Rating Before: M1 = 3.37 ED = -23.00 SD = 1.4547 Mood Rating After: M2 = 4.13 [D' = 79.00 a) Circle the correct answer: This study is an example of a(n) 1) Matched pairs design 3)Simultaneous repeated measures design 2) Successive repeated measures design 4) Independent groups design b) In symbols and words, what is the null hypothesis for this experiment? (1 pts) c) In symbols and words, what is the alternative hypothesis for this experiment? (1 pts) d) Calculate the standard error of the difference scores. (2 pts) e) Calculate the t-test. (2 pts) f) What df do you need to determine the critical values? What are the critical values of t for the rejection regions? Assume a = .05. (2 pts) g) What is the conclusion? State in words (in APA format) and include whether we reject or fail to reject the null hypothesis; is there a difference in mood before teenagers exercise and after they exercise? (Note: You don't need to include standard deviations in your APA write up because they were not given). (2 pts)