Shipping costs at Climer Fisheries Inc. are a mixed cost with variable and fixed cost components. Records indicate the company shipped 6,000 tons of halibut for $5,000 in March and 9,000 tons for $7,000 in April. Assuming that this activity is within the relevant range, the expected shipping cost for shipping 7,800 tons would be:
A.) $6,240
B.) $9,750
C.) $6,440
D.) $6,200