A sales budget is given below for one of the products manufactured by the Key Co.: January February March April 21,000 units 36,000 units 61,000 units 41,000 units 31,000 units May June 25,000 units The inventory of finished goods at the end of each month should equal 20% of the next month's sales. However, on December 31, the finished goods inventory totalled only 4,000 units. Each unit of product requires three specialized electrical switches. Since the production of these specialized switches by Key's suppliers is sometimes irregular, the company has a policy of maintaining an ending inventory at the end of each month equal to 30% of the next month's production needs. This requirement had been met on January 1 of the current year. Required: (Show all your calculations) Prepare a budget showing the quantity of switches to be purchased each month for January, February, and March, and in total for the quarter.