Instructions

Consider COGS.xIsx. Apply the following

forecasting methods to forecast two years:

Implement each model in a separate

spreadsheet.

Plot the data. How would you describe

the data in terms of seasonality and

trend?

Moving average using $k=12.$

Weighted moving average using $k=12$

$($find $w_i$ using solver$)$

Exponential Smoothing $($find a using

solver$)$

Stationary Additive seasonal effect $($find

a and $$ using solver$)$

Stationary Multiplicative seasonal effect

$($find $$ and $$ using solver$)$

Double moving average $(k=12)$

Holt's method

Holt$-$Winter's method for additive

seanonal

Holt$-$Winter's method for multiplicative

seanonal

Seasonal Regression

Which model is the best for this dataset?

Compare each method based on MSE.