c$.$ Prepare a naive forecast for periods $2$ through $11$ using the given sales data. Compute each of the following; $(1)$ MSE, $(2)$ MAD, $(3)$ tracking signal at month $10,$ and $(4)2s$ control limits$.($Negative values should be indicated by a minus sign. Round your answers to $2$ decimal places.$)$

$\backslash$table$[[$MSE$,,1,134\mathrm{.}38$