Question $1$:

A company has recorded sales in last $4$ years over fall, winter, and summer. Data is provided in Excel worksheet Forecasting, perform the following tasks using Excel $($related formulas are given in Excel$)$ Marks$).$ Keep two decimal places.

a$.$ Using a three$-$period moving average $(3$MA$)$ to forecast sales for periods $1$ to $12.$ Put the results in column F$.($Use Data Analysis $$ Movin Averages$)$

Calculate MSE in column G $($cell G$5).$ Write down result in the area specified in the excel sheet.

b$.$ Using exponential smoothing with alpha $=0\mathrm{.}4$ to forecast sales for periods $1$ to $12$ in column H$.($Use Data Analysis $$ Exponential Smoothing$).$

Calculate MSE in column I $($cell I$5).$ Write down result in the area specified in the excel sheet.

c$.$ Consider that data has data may have seasonality and trend. Prepare the data set $($Column L$-$R$).$ Use multiple regression $($Data Analysis $$ regression $$ output range V$6)$ to get the output to check if multiple regression technique is suitable.

d$.$ Using the coefficients obtained in the output $($R $20,21,22).$ Alternatively, you can use TREND function.

Forecast for $Y5$ fall $,$ winter, and summer

Calculate MSE in column S $($cell S$5).$

e$.$ What was your conclusion. Which method is best suited for this data.