The Goodson Company manufactures four different products that it ships to customers throughout Canada.

Breakage cost is very expensive, and Goodson would like to select a mode of delivery that reduces the amount of product breakage. The managers have decided to examine the dollar amounts of breakage incurred by the three alternative modes of transportation under consideration. The executives conducting the study wish to control for differences due to type of product. The company randomly assigns each product to each carrier and monitors the dollar amounts of breakage that occur over the course of 100 shipments. The dollar amounts of breakage per shipment (to the nearest dollar) are as follows:

Rail Plane Truck Product 1 $7,960 $8,053 $8,818 Product 2 $8,399 $7,764 $9,432 Product 3 $9,429 $9,196 $9,260 Product 4 $6,022 $5,821 $5,676

a. Was the Goodson Company correct in its decision to block for type of product? Conduct the appropriate hypothesis test using a level of significance of 0.01.

b. Is there a difference due to carrier type? Conduct the appropriate hypothesis test using a level of significance of 0.01.