TipTop Flight School offers flying lessons at a small municipal airport. The school's owner and manager has been attempting to evaluate performance and control costs using a variance report that compares the planning budget to actual results. A recent variance report appears b elow: TipTop Flight School Variance Report For the Month Ended July 31 Actual Planning Results Budget Variances 200 Lessons Revenue 205 $42,920 42,000 $920 F Expenses 12,980 2,800 180 U 7,400 185 U 4,000 410 U 3,050 110U 65 F 4,390 80 F Instructor wages rcraft depreciation Fuel Maintenance Ground facility expenses Administration 7,585 4,410 3,160 2,765 4,310 2,830 Total expense 35,210 34,470 740 U Net operating income $ 7,710 7,530 $180 F After several months of using such variance reports, the owner has become frustrated. For example, she is quite confident that instructor wages were very tightly controlled in July, but the report shows an unfavorable ariance