20. What is the appropriate statistical analysis to use: t-test for two independent samples, t-test for dependent samples, ANOVA, or chi-square test of independence? Please identify and explain why it is appropriate.

(a) A study was conducted to see whether monetary incentives to use less water during times of drought had an effect on water usage. Sixty single family homeowners were randomly assigned to one of two groups: 1) monetary incentives and 2) no monetary incentives. At the end of three months, the total amount of water usage for each household, in gallons, was measured.

(b) A study was conducted to see whether the mean weight loss is the same for 10 different weight loss programs. Each of the 10 programs had 50 subjects in it. The subjects were followed for 12 months. Weight change for each subject was recorded.