Ratchet company uses budgets in controlling costs. the august 2017 budget report for the company's assembling department is as follows.

ratchet company
budget report
assembling department
for the month ended august 31, 2017
difference
manufacturing costs budget actual favorable, unfavorable, neither favorable nor unfavorable
variable costs
direct materials $55,900 $54,900 $1,000 favorable
direct labor 59,800 56,500 3,300 favorable
indirect materials 26,000 26,100 100 unfavorable
indirect labor utilities 19,500 19,080 420 favorable
utilities 16,250 16,090 160 favorable
maintenance 9,100 9,200 100 unfavorable
total variable 186,550 181,870 4,680 favorable
fixed costs
rent 11,200 11,200 -0- neither favorable nor unfavorable
supervision 16,500 16,500 -0- neither favorable nor unfavorable
depreciation 7,800 7,800 -0- neither favorable nor unfavorable to search
total fixed 35,500 35,500 ? 0? neither favorable nor unfavorable
total costs $222,050 $217,370 $4,680 favorable

the monthly budget amounts in the report were based on an expected production of 65,000 units per month or 780,000 units per year. the assembling department manager is with the report and expects a raise, or at least praise for a job well done. the company president, however, is unhappy with the results for august because only 63,000 units were produced.

a. state the total monthly budgeted cost formula.

b. prepare a budget report for august using flexible budget data.