For each of the following examples, state whether the chi-square goodness-of-fit test or the chi-square test for independence is appropriate, and state the degrees of freedom (df) for the test.

(a) An instructor tests whether class attendance (low, high) and grade point average (low, average, high) are independent.

(b) A student tests whether the professor's speaking style (monotone, dynamic) and student interest (low, high) are independent.

(c) A health psychologist compares the number of lean, healthy, overweight, and obese college students.

(d) A personality psychologist compares the number of single mothers with Type A or Type B personality traits.