Exam 18: Nonparametric Methods

An owner of two cats is trying to decide if it is cheaper to order cat food over the Internet or to buy the food locally. Listed below are the prices (in dollars) quoted for two bags of cat food from various manufacturers. On the average, can we conclude that Internet purchases are significantly less than local store purchases? Test at α = .05

For eight randomly selected states, the following table lists the per capita beer consumption (in gallons) and the per capita wine consumption (in gallons). Calculate the rank correlation coefficient when beer consumption = x, and wine consumption = y.

In a manufacturing facility producing fasteners, a foreman suspects that the diameter of the bolts produced by his first-shift workers is greater than the diameter of the bolts produced by his second-shift workers. He takes a sample of five bolts from the first shift and a sample of four bolts from the second shift and measures the diameters in inches. Below are the results from five first-shift and four second-shift observations. The bolt diameter measurements are not normally distributed. At α = .05, can we conclude that his suspicion is correct?