Using the data in Table 13.3, determine the managerial impact of: (a) an increase in the annual miles operated per tractor/trailer from 100,000 to 125,000; (b) a decrease in the average load per trip form 40,000 pounds to 34,000 pounds; and (c) a 20 percent increase in the price of fuel from $1.10 to $1.32 per gallon.