As purchasing agent for the Horner-Williams Company, you have primary responsibility for securing high-quality raw materials at the best possible prices. One particular material the Horner-Williams Company uses a great deal of is aluminum. After careful study, you have been able to reduce the prospective vendors to three. It is unclear whether these three vendors produce aluminum that is equally durable.
To compare durability, the recommended procedure is to put pressure on aluminum until it cracks. The vendor whose aluminum requires the highest median pressure will be judged to provide the most durable product. To carry out this test, 14 pieces from each vendor have been selected. These data are in the file Horner-Williams. (The data are pounds per square inch pressure.) Using α = 0.05, what should the company conclude about whether there is a difference in the median strength of the three vendors’ aluminum?