Details of operating income are as follows:
2019:
Revenues (product of $100 per unit and 40,000 units): $4,000,000
Costs
Direct material costs (product of $10 per square feet and 120,000 square feet): 1,200,000
Conversion costs (product of $20 per unit and 50,000 units): 1,000,000
Selling and customer-service cost (product of $24,000 per customer and 30 customers): 720,000
Total costs: 2,920,000
Operating income: $1,080,000
2020:
Revenues (product of $110 per unit and 42,000 units): $4,620,000
Costs
Direct material costs (product of $11 per square feet and 123,000 square feet): 1,353,000
Conversion costs (product of $22 per unit and 50,000 units): 1,100,000
Selling and customer-service cost (product of $25,000 per customer and 29 customers): 725,000
Total costs: 3,178,000
Operating income: $1,442,000
Change in operating income (Difference of $1,442,000 and $1,080,000): $362,000 F.