How to Add Trendlines

1. Open the workbook in Excel, locate the spreadsheet containing the chart and click on it.
2. Select 'Chart' and then choose 'Add Trendline' from the toolbar menu.
3. Go to the Type tab and under 'Based on Series,' highlight the series that you want to add a trendline to.
4.
Go to the 'Type/Regression' section and select from either 'Linear,' 'Logarithmic,' 'Polynomial,' 'Power,' 'Exponential' or 'Moving Average.' (NOTE: If you choose 'Polynomial,' you will also be able to pick the independent variable's power. If you choose 'Moving Average,' you will also be able to choose the period amounts.)
5.
Go to the Options tab and, if desired, type in a more descriptive trendline name in the 'Custom' text box; otherwise, select the option for the default suggested name located next to 'Automatic.' Click 'OK' when finished.