Use the $3-$period Weighted Moving Average forecasting model to develop a prediction for the $$passenger miles$$ for the next week $($i$.$e$.,$ week $13).$ Please use the weights of $3$ for the most recent week, $2$ for two weeks prior, and $1$ for three weeks prior.$$ Calculate the MAD error term.

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ACTUAL PASSANGER

WEEK

MILES $(1,000$s$)$

$1$

$17$

$2$

$21$

$3$

$19$

$4$

$23$

$5$

$18$

$6$

$16$

$7$

$20$

$8$

$18$

$9$

$22$

$10$

$20$

$11$

$15$

$12$

$22$