Using a $3-$month moving average $($with weights of $6,3,$ and $1$ for the most current value, next most current value, and oldest value, respectively$),$ the forecast value for November in the following time series is:

July $5$

Aug $11$

Sept $12$

Oct $6$

Question $5$ options:

$1)$

$11\mathrm{.}60$

$2)$

$10\mathrm{.}00$

$3)$

$9\mathrm{.}67$

$4)$

$8\mathrm{.}30$

$5)$

$8\mathrm{.}60$