Question

A study of 10 different weight loss programs involved 500 subjects. Each of the 10 programs had 50 subjects in it. The subjects were followed for 12 months. Weight change for each subject was recorded. The researcher wants to test the claim that all ten programs are equally effective in weight loss. (a) Which statistical approach should be used? (i) confidence interval (ii) t-test (iii) ANOVA (iv) Chi square (b) Explain the rationale for your selection in (a). Specifically, why would this be the appropriate statistical approach?

Answer 1

a)iii)ANOVA.

Let us consider each weight loss programs as treatments and we are interested whether the between group variances vary that is whether the group means are all equal or atleast one is different.If the group emans are all equal then it will mean that all the ten types of weight loss programs are equally effective otherwise not. Hence this is a classic ANOVA setup. Moreover we are interested in the between group variabuility rather than the within group variability.

Here the groups are the group of subjects in each weight loss programs.