The Carbondale Hospital is considering the purchase of a new ambulance. The decision will rest partly on the anticipated mileage to be driven next year. The miles driven during the past $5$ years are as$$ follows:

$$

Year

$1$

$2$

$3$

$4$

$5$

Mileage

$3$ comma $100$

$4$ comma $050$

$3$ comma $450$

$3$ comma $850$

$3$ comma $750$

Part $2$

$$a$)$ Using a$2-$year moving$$ average, the forecast for year $6=$

$$

$3800$ miles $($round your response to the nearest whole$$ number$).$

Part $3$

$$b$)$ If a$2-$year moving average is used to make the$$ forecast, the MAD based on this$=$

$$

miles $($round your response to one decimal$$ place$).($Hint: You will have only $3$ years of matched$$ data.$)$