A company has these Budgeted sales for the upcoming quarter.

January = 15,000 units

February = 18,000 units

March = 16,500 units

The ending finished goods inventory for each month equals 50% of next month's budgeted sales. Additionally, 3 pounds of raw material is required for each unit of finished product. The ending raw materials for each month 200% of the next month's production requirements. If the raw materials cost $4 per pound and must be paid for in the month purchased, the budgeted raw materials purchases (in $) for January are:

The answer is 216,000. I just need the calculations on how to come to this answer.