Fitzpatrick Inc. planned and manufactured 500,000 units of its single product in 2016, its first year of operations. Variable manufacturing costs were $40 per unit of production. Planned fixed manufacturing costs were $1, 200,000. Marketing and administrative costs (all fixed) were $500,000 in 2016. Fitzpatrick sold 450,000 units of products in 2016 at $50 per unit. Required: 1. Determine Fitzpatrick Inc's operating income using full costing. 2. Determine Fitzpatrick Inc's operating income using variable costing. 3. Explain the difference between the operating incomes in requirements 1 and 2