What test of differences is appropriate in each of the following situations and why ?
(a) Average campaign contributions of Democrats, Republicans, and Independents are to be compared.
(b) Managers and supervisors have responded "yes," "no," or "not sure" to an attitude question. Their answers are to be compared.
(c) One-half of a sample receives an incentive in a mail survey. The other half does not. A comparison of response rates is desired.
(d) Stockbrokers in the East, Midwest, and West were asked their annual incomes. Regional comparisons are to be made.
The solution provides step by step method for the calculation of test statistic . Formula for the calculation and Interpretations of the results are also included.