Moncrief corporation bases its budgets on machine-hours. the company's static planning budget for july appears below: budgeted number of machine-hours 1,000 supplies (@ $8.60 per machine-hour) $ 8,600 power (@ $8.80 per machine-hour) 8,800 salaries 11,300 equipment depreciation 9,900 total $ 38,600 actual results for the month were: actual number of machine-hours 1,200 supplies $ 10,290 power $ 10,860 salaries $ 11,690 equipment depreciation $ 9,990 the spending variance for supplies costs in the flexible budget performance report for the month should be: multiple choice $30 f $1,690 f $1,690 u $30 u