My only question is how to find the beginning inventory for January when December's numbers are not given.

Preston Manufacturing produces self-watering planters for use in upscale retail establishments. Sales projections for the first five months of the upcoming year show the estimated unit sales of the planters each month to be (Click the icon to view additional information) Inventory at the start of the year was 390 planters The desired inventory of planters at the end of each month should be equal to 10% of the following month's budgeted sales. Each planter requires three pounds of polyprop company wants to have 20% of the polypropylene required for next month's production on hand at the end of each month. The polypropylene costs $0.25 per pound. Read the reguitements Requirement 2. Prepare a direct materials budget for the polypropylene for each month in the first quarter of the year, including the pounds of polypropylene required and the total cost of the polypropylene to be purchased Start by preparing the direct matenals budget through the total quantity needed, then complete the budget Preston Manufacturing Direct Materials Budget For the Months of January through March Data Table January February March Quarter Units to be produced 3.880 3.640 3,240 10,760 Number of planters to be sold Multiply by Quantity of direct materials needed per unit 3 January 3.900 Quantity needed for production 11.640 10.920 9,720 32 280 February 3,700 Plus Desired ending inventory of direct materials 2 184 1.944 2,724 2.724 March 3,100 Total quantity needed 13,824 12.864 12 444 35 004 April 4,500 Less 1164 1,944 Beginning inventory of direct materials 1164 May 4.900 Quantity to purchase 10.680 10.500 33840 S 0.25 $ 0.25 $ 0.25 $ Multiply by Cost per pound 0.25 3165 $ 2 670 $ 2.625 8460 Total cost of direct material purchases Print Done 2.184 12660 Enter any number in the edit fields and then click Check