Butler Corporation has forecast production for the next four months as follows: July 14,900 units, August 16,500 units, September 17,800 units, and October 18,200 units. Manufacturing overhead is budgeted to be $18,500 (depreciation $2,100, supervision $7,100, factory lease $1,600, maintenance $4,100, training $3,600 ) plus $5 per unit produced ( $3 indirect materials, $2 utilities)