The Universal Computer Company wants to forecast the monthly sales of their newly introduced tablet computer using the following historical sales data:

Month

Sales $($units$)$

$1$

$8,000$

$2$

$10,000$

$3$

$12,500$

$4$

$11,000$

$5$

$10,500$

$6$

$11,500$

$7$

$11,000$

Use the $3-$month weighted moving$-$average method to calculate the forecast for month $8$ using weights of $0\mathrm{.}50,0\mathrm{.}30,$ and $0\mathrm{.}20,$ where $0\mathrm{.}50$ refers to the weight for the most recent demand.