$($a$)$ Calculate the single exponential smoothing forecast for these data using an $\backslash$alpha of $0\mathrm{.}30$ and an initial forecast $($F$1)$ of $31.$

$($b$)$ Calculate the exponential smoothing with trend forecast for these data using an $\backslash$alpha of $0\mathrm{.}30,$ a $\backslash$delta of $0\mathrm{.}30,$ an initial trend forecast $($T$1)$ of $1,$ and an initial exponentially smoothed forecast $($F$1)$ of $30.$

$($c$)$ Calculate the mean absolute deviation $($MAD$)$ for each forecast. Which forecasting model $($with or without trend$)$ is better?