Three different diets, called blue, red, and green, respectively, are recommended to three different groups of people with similar physical features. The file Diet contains the weight each participant lost (in kilograms) after following the diet for six months.

a. At the 0.05 level of significance, is there evidence of a difference in the mean weight loss for the different diets?

b. If appropriate, determine which diets differ in mean weight loss.

c. At the 0.05 level of significance, is there evidence of a difference in the variation in the mean weight loss from the three diets?