An industrial engineer employed by a beverage bottler is interested in the effects of two different types of 32-ounce bottles on the time to deliver 12-bottle cases of the product.

The two bottle types are glass and plastic. Two workers are used to perform a task consisting of moving 40 cases of the product 50 feet on a standard type of hand truck and stacking the cases in a display. Four replicates of a 22 factorial design are performed, and the times observed are listed in the following table. Analyze the data and draw appropriate conclusions. Analyze the residuals and comment on the model’s adequacy.

Worker Bottle Type 1 2 Glass 5.12 4.89 6.65 6.24 4.98 5.00 5.49 5.55 Plastic 4.95 4.43 5.28 4.91 4.27 4.25 4.75 4.71