Dawes Designs buys T$-$shirts for clubs, teams, and other organizations. Dawes takes the shirts and adds the organization's logo$.$ Because of the uncertainty in the timing of the sales and to avoid stock outages, Dawes tries to maintain an inventory of shirts equal to two$-$month's of sales. The shirts cost $$15\mathrm{.}50$ each and must be paid for in cash. On June $30$ of the current year, the company expects to have $16,500$ shirts in stock. Sales estimates, based on contracts received and historical data, are as follows for the next six months:

July $7,920$

August $10,890$

September $8,360$

October $8,910$

November $6,380$

December $5,060$

Required:

a$.$ & b$.$ Estimate purchases $($in units$)$ and cash required to make purchases in July, August, and September.