On May $1,$ Sandhill Company had beginning inventory consisting of $294$ units with a unit cost of $$6.$ During May, the company purchased inventory as follows:

$588$ units at $$6$

$882$ units at $$7$

The company sold $1470$ units during the month for $$11$ per unit. Sandhill uses the average$-$cost method. Assuming that a periodic inventory system is used, the weighted$-$average unit cost for May is

$$6\mathrm{.}00.$

$$6\mathrm{.}60$

$$6\mathrm{.}50.$

$$7\mathrm{.}00.$