Are parents of girls more inclined to buy them a car when they leave for college than parents of boys? simple random samples of 40 girls and 45 boys are taken from a large university on the west coast. when interviewed, 20 girls and 21 boys in the sample responded that their parents bought them a car. what is a 95% plus four confidence interval for the difference in population proportions of girls and boys whose parents bought a car for them when they left for college? use girls as group 1 and