Problem $2$

Two independent methods of forecasting based on judgment and experience have been prepared

each month for the past $10$ months. The forecasts and actual sales are as follows:

a$)$ Compute the Mean Absolute Deviation $($MAD$)$ for each forecast

b$)$ Compute the Mean Squared Error $($MSE$)$ for each forecast

c$)$ Compute the Cumulative Forecast Error $($CFE$)$ for each forecast

d$)$ Which forecast do you prefer and why? Can you please give answer for all four questions $?$