Pulling wood apart. How heavy a load (pounds) is needed to pull apart piecesof Douglas

Chapter 0, Problem 14.26

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Pulling wood apart. How heavy a load (pounds) is needed to pull apart piecesof Douglas fir 4 inches long and 1.5 inches square? Here are data from studentsdoing a laboratory exercise:33,190 31,860 32,590 26,520 33,28032,320 33,020 32,030 30,460 32,70023,040 30,930 32,720 33,650 32,34024,050 30,170 31,300 28,730 31,920 (a) We are willing to regard the wood pieces prepared for the lab session as anSRS of all similar pieces of Douglas fir. Engineers also commonly assume thatcharacteristics of materials vary Normally. Make a graph to show the shape of thedistribution for these data. Does the Normality condition appear safe? Supposethat the strength of pieces of wood like these follows a Normal distribution withstandard deviation 3000 pounds.(b) Give a 90% confidence interval for the mean load required to pull the woodapart. Follow the four-step process in your work.