You should start and save a new Tableau file for each Chapter. Roger Company$$s files can be downloaded from Connect in Excel format $($Click here$).$ For Chapter $5,$ you will import the Roger Company shipping file. See Chapter $4$ for instructions on how to import Excel files to Tableau.

In this question, we will use Tableau$$s forecast function to forecast sales in $2021$ Q$4,$ and then compare forecasted sales to actual values as a final$/$review analytical procedure. Roger Company management has acknowledged that monthly sales are volatile.

After importing the shipping file, open a new worksheet $($tab$)$ and call it Q$4$ Forecast.

To perform a forecast, first right$-$click on Invoice Date and convert to a Continuous value.

Add Invoice Total to the Rows line, and Invoice Date to the Columns line.

Expand the invoice date until sales are shown by month.

Add Invoice Date from Dimensions to the Filter pane, select Range of Dates, and set the date filter to include all invoices through September $30,2021.$

To add the forecast, click on the $$Analytics$$ tab next to the $$Data$$ tab towards the top$-$left corner of Tableau.

Under Model, drag and drop Forecast on the line chart.

Left$-$click on the flat forecast line, and press Edit to change Forecast options.

We only want to forecast $2021$ Q$4,$ so change to forecast exactly three months, ignoring $0$ months.

Change the Forecast Model from Automatic to Custom, and add in Additive trend. Click OK$.$