PLEASE HELP ASAP!! WILL UPVOTE AND LIKE!!

I cant seem to figure out how to find the cost drivers / what they would be to finish building this Flexible Budget Performance Report. Please solve for the missing value and show work. Thank you.

Several years ago, Westmont Corporation developed a comprehensive budgeting system for planning and control purposes. While departmental supervisors have been happy with the system, the factory manager has expressed considerable dissatisfaction with the information being generated by the system. A report for the company's Assembly Department for the month of March follows: After receiving a copy of this cost report, the supervisor of the Assembly Department stated, "These reports are super. It makes me feel really good to see how well things are going in my department. I can't understand why those people upstairs complain so much about the reports:" For the last several years, the company's marketing department has chronically failed to meet the sales goals expressed in the company's monthly budgets. Complete the new performance report for the quarter, based on Flexible Budget Performance approach. (Do not round your intermediate calculations. Indicate the effect of each variance by selecting "F" for favorable, " U " for unfavorable, and "None" for no effect (i.e, zero varlance). finput all amounts as positive values.)