To set X-bar chart upper and lower control limits, one must know the process central line, which is the: Select one: a. total number of defects in the random samples O b. average of the sample means O c. size of population d. average percent defects in the random samples O e. standard deviation of average fraction defective

8. Averaging techniques are useful for: A. distinguishing between random and non-random variations B. smoothing out fluctuations in time series C. eliminating historical data D. providing accuracy in forecasts E. average people

4.  Cartons of Plaster of Paris are supposed to weigh exactly 32 oz. Inspectors want to develop process control charts. They take 5 samples of 6 boxes per sample and weigh them. Based on the following data, what are the lower and upper control limits for the 3-sigma mean chart and the range chart, respectively? Please keep two decimal places and select the best answers.   Select one: a. [33.8, 34.76], [0, 2.00] b. [33.96, 34.60], [0, 1.18] c. [34.01, 34.55], [0, 1.12] d. [34.01, 34.55], [0.52, 2.52] e. [32.6, 35.96], [0, 1.12]

10. To monitor the quality of pepperoni pizzas, a quality control manager collects random samples of pizzas and evaluates them. The process mean and standard deviation for the weight and diameter of pizzas are not known. Which of the following(s) is a correct matching between the type of data collected and the choice of control chart used? Select all correct matchings.      Select one: a. The manager weighed the sampled pizzas and constructed a c-chart.  b. The manager rated the appearance of sampled pizzas as acceptable or unacceptable and then constructed a c-chart.  c. The manager counted the number of pepperonis per each inspected pizza and constructed a mean chart.  d. The manager measured the diameter of the sampled pizzas and constructed a range chart.