Question

Since October 2008 chain restaurants in California are required to display calorie counts of each menu item. Prior to menus displaying calorie counts, the average calorie intake of a diner at a CPK restaurant was 1900 kcal. A nutritionist conducts a hypothesis test to see if there has been a significant decrease in the average calorie intake of CPK diners. The nutritionist takes a random sample of 30 CPK diners who have a mean calorie intake of 1806 calories with a sample standard deviation of 319 calories.

Do we reject the null hypothesis at 0.05 level? What about at 0.10 level?

Select one:

a. Reject the null hypothesis at 0.05 level, not reject the null hypothesis at 0.10 level.

b. Fail to reject the null hypothesis at both 0.05 and 0.10 level.

c. Reject the null hypothesis at both 0.05 and 0.10 level.

d. Fail to reject the null hypothesis at 0.05 level, but reject the null at 0.10 level.

Answer 1