Practical meaning. A test of the hypothesis that the Zone diet is effective (when used for one year) results in the following conclusion: There is sufficient evidence to support the claim that the average weight change is less than 0 (so that there is a weight loss). The sample of 40 subjects had a mean weight loss of 2.1 pounds (according to data from "Comparison of the Atkins, Ornish, Weight Watchers, and Zone Diets for Weight Loss and Heart Disease Reduction", by Dansinger et al., Journal of the American Medical Association, vol 293, No. 1). Is the weight loss of 2.1 pounds statistically significant? Does the weight loss of 2.1 pounds have a practical significance? Explain