At Rumsey’s Old Fashion Roast Beef, cola drinks are filled by an automatic machine whose operation is based on the weight of the drink. When the process is in control, the machine fills each cup so that the grand mean is 10.0 ounces and the mean range is 0.25 for samples of 5.
a. Determine the upper and lower control limits for the process for both the mean and the range.
b. The manager of the I-280 store tested five soft drinks served last hour and found that the mean was 10.16 ounces and the range was 0.35 ounce. Is the process in control? Should other action be taken?