Two different types of injection-molding machines are used to form plastic parts. A part is considered defective if it has excessive shrinkage or is discolored. Two random samples, each of size 300, are selected, and 15 defective parts are found in the sample from machine 1, while 8 defective parts are found in the sample from machine 2. Is it reasonable to conclude that both machines produce the same proportion of defective parts? Use = 0.05. (a) Test the hypothesis Ho: p1 = p2 verses H1: p1 #p2. What is zo? Round your answer to two decimal places (e.g. 98.76). Zo-i (b) Is it reasonable to conclude that both machines produce the same proportion of defective parts? stical Tables and Charts Yes. No.