SSTA032 TUTORIAL QUESTIONS 2017 Pack A B C D E T Number of pens 3 12 4 4 6 3 Number of defective pens 0 2 0 1 O (a) Calculate the ratio estimator of the population mean for the defective ball pen in the shipment and place a bound on the error of estimation. (b) Estimate the total number of defective ball pens in the shipment and place a bound on the error of estimation. EXERCISE 2 (a) Use the sample data in EXERCISE 1 to find the appropriate sample size needed to estimate the proportion of defective ball pens with a bound of 5% on the error of estimation. (b) If you knew that there were 300 pens in the shipment, use this additional information to give a different estimate than in EXERCISE 1(b) of the total number of defective ball pens in the shipment, and place a bound on the error of estimation