Shipping cost at Junk Food Imports is a mixed cost with variable and fixed components. Past records indicate total shipping cost was $18,000 for 16,000 pounds shipped and $22,500 for 22,000 pounds shipped. Assuming that this activity is within the relevant range, if the company plans to ship 18,000 pounds next month, the expected shipping cost is: $18,500 $20,400 $19,500 $24,000 must show work