$16)$ Please compute all forecasts, and forecast errors. Please be sure to show your work for at least one period for each forecast and forecast error. $($Only numbers will result in a ZERO on this problem$).[$Note the X and Y bar, and the slope are specified below$].$

$17)$ Once All forecasts are specified below, please circle the best forecast in an alternate color, and comment on why this is the best forecast.

$18)$ Compute the forecast for the $11$ period for the forecast models where this is possible.