The number of disk drives $($in millions$)$ made at a plant in Singapore during the past $9$ years follows:

Year Disk Drives

$1168$

$2175$

$3201$

$4196$

$5222$

$6220$

$7221$

$8215$

$9218$

a$.$ Forecast the number of disk drives to be made next year $($year $10),$ using trend analysis

$237\mathrm{.}67$

b$.$ What is the forecast for year $12?$

$[$ Select $]$

c$.$ Using forecasts from the trend equation between year $1$ and $9,$ compute the mean absolute error $($MAD$)$ for this approach