A manager has just received an evaluation from an analyst on two

potential forecasting methods. The analyst is indifferent between the two

methods, saying that they should be equally accurate and in control. The

demand and the forecasts using the two methods for nine periods follow:

LO$7$

Period: $123456789$

Demand: $373937394549474951$

Method $1$: $363840424646464852$

Method $2$: $363738384152474852$

a$.$ Calculate the MSE for each method and compare the two methods.

b$.$ Construct a $2$s control chart for each method and interpret them. Do

you agree with the analyst? Explain.