Question $25(6\mathrm{.}25$ points$)$

Sales for the last eight weeks are as follows:

Week

Sales

$1$

$60$

$2$

$58$

$3$

$51$

$4$

$72$

$5$

$65$

$6$

$60$

$7$

$79$

$8$

$62$

Using a $\mathrm{.}50-\mathrm{.}40-\mathrm{.}10$ weighted moving average, what is the sales forecast for Week $9?$