3) A researcher is interested in the impact that exercise has on mood. The researcher has 18 subjects exercise on a regular basis for two weeks. At the end of two weeks the subjects complete a standardized mood questionnaire. The average mood score of across the population on this questionnaire is a 45 but the standard deviation is unknown. The sample of 18has a higher average mood score of 51 with a standard deviation of 8.5. (Assume that higher scores represent elevated mood.)

a. Write a set of statistical hypothesis statements for this situation.

b. Determine a t value for this sample.

c. Discuss what the researcher should conclude and why.