Directions: Use the information in the scenarios to complete the hypothesis testing process. Your final answer for each scenario should include all four parts of Step 6.

Scenario 1

A researcher wanted to examine whether there were health benefits to daily consumption of vitamin C. A randomly selected sample of 94 adults was asked to consume a daily dose of vitamin C. The participants' overall health was assessed before the vitamin C intervention (M_{PreIntervention} = 43.57) and three months after the intervention began (M_{PostIntervention} = 48.35). The standard deviation of the difference between the two means was s_D = 3.28. Does daily consumption of vitamin C increasepeople's overall health? Usea = .05. If appropriate, calculate a confidence interval and provide information about the size of the effect.

Scenario 2

Dr. Patel wanted to assess whether the use of extrinsic rewards increased the number of books that middle school students read. She selected a random sample of 105 middle school students. Then she calculated that, on average, the students in the sample read 5.87 books per month. Next, she implemented a month-long intervention: for each book a student read, the student received a $5 gift card. Finally, she calculated the average number of books the students read during the intervention: 8.43. The standard deviation of the difference between the two means was s_D = 2.54. Did the extrinsic reward increase the number of books students read? Use a = .05. If appropriate, calculate a confidence interval and provide information about the size of the effect.