A study was conducted in which students were asked to estimate the number of calories in a cheeseburger. One group was asked to do this after thinking about a calorie-laden cheesecake. A second group was asked to do this after thinking about an organic fruit salad. The mean number of calories estimated was 772 for the group that thought about the cheesecake and 1046 for the group that thought about the organic fruit salad. Suppose that the study was based on a sample of 20 students in each group, and the standard deviation of the number of calories estimated was 128 for the people who thought about the cheesecake first and 144 for the people who thought about the organic fruit salad first.
The null and alternative hypotheses are:
H0: μ1 ≥ μ2
H1: μ1 < μ2
a. Assume the population variances are not equal. At the 0.10 level of significance, is there evidence that the mean estimated number of calories in the cheeseburger is lower for the people who thought about the cheesecake first than for the people who thought about the organic fruit salad first?
Find the test statistic:
tSTAT =
p-value =