Current Attempt in Progress

A company has used three different methods to forecast sales for the past five months.

$($a$)$ Use MAD and MSE to evaluate the performance of the three methods.

$($Round your answers to $1$ decimal place, e$.$g$.1\mathrm{.}2.)$

Method A

Method B

Method C

$($b$)$ Which of these is actually the na$$ve method?