An оil well service cоmpаny meаsures its оutput by the number of wells serviced. The compаny has provided the following fixed and variable cost estimates that it uses for budgeting purposes. Fixed Element per MonthVariable Element per Well ServicedRevenue $4,200Employee salaries and wages$41,300$1,200Servicing materials $ 500Other expenses$33,000 When the company prepared its planning budget at the beginning of June, it assumed that 33 wells would have been serviced. However, 31 wells were actually serviced during the month.The amount shown for net operating income in the planning budget for the month would have been closest to: