if productive capacity of 100% was 13,000 hours and the total factory overhead cost budgeted at the level of 8,000 standard hours was $202,750, determine the variable factory overhead controllable variance, fixed factory overhead volume variance, and total factory overhead cost variance. the fixed factory overhead rate was $3.75 per hour. enter a favorable variance as a negative number using a minus sign and an unfavorable variance as a positive number.