4519p 17.38 Pulling Apart Wood. How heavy a load (in pounds) is needed to pull apart pieces of Douglas r 4 inches long and 1.5 inches square? Here are data from students doing a laboratory exercise: ||III WOOD 33,190 31,860 32,590 25,520 33,280 32,320 33,020 32,030 30,460 32,700 23,040 30,930 32,720 33, 550 32,340 24,050 30,170 31,300 28,730 31,920 We are willing to regard the wood pieces prepared for the lab session as an SR8 of all similar pieces of Douglas r. Engineers also commonly assume that characteristics of materials vary Normally. Suppose that the strength of pieces of wood like these follows a Normal distribution, with standard deviation 3000 pounds. a. Is there statistically signicant evidence at the a : 0.10 level against the hypothesis that the mean is 32,500 pounds for the two- sided alternative? b. Is there statistically signicant evidence at the a = 0.10 level against the hypothesis that the mean is 31,500 pounds for the two- sided alternative