work. Indicate clearly the methods you use, because you will be graded on the correctness of your methods as well as on the accuracy and completeness of your results and explanations. 1. A company that sells glassware has two manufacturing plants. In a quality control inspection of a random sample of 150 pieces of glassware from plant A, 8% of the pieces had a defect. In a random sample of 200 pieces from plant B, 6% of the pieces had a defect. a. Construct and interpret a 99% confidence interval for the true difference in the proportion of pieces from plant A that are defective and the proportion of pieces from plant B that are defective. Use the four step process. b. Based on this confidence interval, is there convincing evidence that the true proportion of pieces from plant A that are defective is different from the true proportion of pieces from plant B that are defective? Explain