Accounting homework help!

Midland Company buys tiles and prints different designs on them for souvenir and gift stores. It buys the tiles from a small company in Europe, so at all times it keeps on hand a stock equal to the tiles needed for three months' sales. The tiles cost $1.00 each and must be paid for in cash. The company has 28,000 tiles in stock. Sales estimates, based on contracts received, are as follows for the next six months: Estimate purchases (in units) and cash required to make purchases in January, February, and March