A hypothesis test that the Zone diet is effective when used

A hypothesis test that the Zone diet is effective (when used for one year) results in this conclusion: There is significant evidence to support the claim that the mean weight change is less than 0 (so there is a loss of weight). The sample of 40 subjects had a mean weight loss of 2.1 lb. Does this indicate that the diet is effective?

Solution

Yes, because there is significant evidence that there is a loss of weight.