Example 15-3 A particular type of steel beam has been designed to have a compressive strength (lb/inz) of at least 50,000. For each beam in a sample of 25 beams, the compressive strength was determined and is given in the table below. Assuming that actual compressive strength is distributed symmetrically about the true average value, let's use the Wilcoxon test with a = 0.01 to decide whether the true average compressive strength is less than the specied valuethat is, test H0: ,4 = 50,000 versus Ha: ll