Weight Loss from Different Diets A study of the Atkins, Zone, Weight Watchers, and Ornish weight loss programs involved 160 subjects. Each program was followed by 40 subjects. The subjects were...

Weight Loss from Different Diets
A study of the Atkins, Zone, Weight Watchers, and Ornish weight loss programs involved 160 subjects. Each program was followed by 40 subjects. The subjects were weighed before starting the weight loss program and again one year after being on the program. The ANOVA results from Excel are given below (based on data from “Comparison of the Atkins, Ornish, Weight Watchers, and Zone Diets for Weight Loss and Heart Disease Risk Reduction,” by Dansinger, et al., Journal of the American Medical Association, Vol. 293, No. 1). Use a 0.05 significance level to test the claim that the mean weight loss is the same for the diets. Given that the mean amounts of weight loss after one year are 2.1 lb, 3.2 lb, 3.0 lb, and 3.3 lb for the four diets, do the diets appear to be effective?