Question: In a quality-control procedure used in your plant, 150 bottles of a soft drink are inspected every two hours. The variable measured is the amount of the secret ingredient (measured in grams per bottle) used in producing the product. Assume that past experience shows that the mean level of the ingredient is .5 grams and the standard deviation is .07 grams. Further, assume that the quality-control people have decided to establish an upper limit to that level, above which the production process is stopped for readjustment. Given that the quality-control people desire to have only a 5% probability of obtaining a sample mean above that level when they inspect the 150 bottles, what is the upper control limit?