Find the test statistic and do the two-sample test for equality of proportions.
a. Repeat buyers at two car dealerships: p1 = .30, n1 = 50, p2 = .54, n2 = 50, left-tailed test.
b. Honor roll students in two sororities: p1 = .45, n1 = 80, p2 = .25, n2 = 48, two-tailed test.
c. First-time Hawaii visitors at two hotels: p1 = .20, n1 = 80, p2 = .32, n2 = 75, left-tailed test.