1. A paint manufacturer wishes to compare the drying times of two different types of paint. Independent random samples of 11 cans of A and 9 cans of B were selected and applied to similar surfaces. The drying times (in hours) were recorded. The summary statistics are as follows:

A B_

Sample mean76.7 hrs65.6 hrs

Sample SD4.5 hrs5.1 hrs

Sample size119

Use this data along with a0.01 significance level to test the claim that the mean drying time for paint type A is equal to the mean drying time for paint type B.

A statistics professor at an all-women's college determined that the standard deviation of women's heights is 2.5 inches. The professor claims that men's heights are more variable than women's heights. To test the claim, he randomly selected 41 male students from a nearby all-male college and found the standard deviation to be 2.9 inches. Use this sample data and a signicance level of o = 0.01 to test the professor's claim that the standard deviation of male heights is greater than 2.5 inches. Find the standardized test statistic t for a sample with n = 12, x-bar = 15.7, and s = 2.1. Assume that we will use a signicance level of a = .01. and the alternative hypothesis is Ha: u # 16.2. 0 {mos O {1325 O D.381 O {3.037