Zephyr is a manufacturer of paper towels, napkins, and toilet paper. The manager of the Zephyr factory in South Carolina needs your help as an analyst to forecast sales of their Select$-$A$-$Size Paper Towel packs. The sales data for this product in the past $12$ months is shown below $($Note that month $1$ refers to sales made $12$ months ago. Month $12$ refers to sales made last month.$)$:

Month Sales $($in millions of packs$)$

$11335$

$21334$

$31340$

$41342$

$51353$

$61358$

$71375$

$81376$

$91407$

$101423$

$111470$

$121498$

Quesiton $12$: You have realized that the sales for Select$-$A$-$Size Paper Towel packs have been increasing over the past year. You have learned that the double exponential smoothing method can account for such a trend in the data.

Use double exponential smoothing method to forecast sales for months $2$ to $12,$ assuming S$\_1=1335$ T$\_1=15$ and set a $($alpha$)=0\mathrm{.}8$ B $($beta$)=0\mathrm{.}2$

What is the forecast for the $10$th month? If your answer is not an integer, provide at least three decimal places, e$.$g$.,7\mathrm{.}500.$