In this quick tutorial, we will be using trendlines in PowerPoint 2010. In a prior tutorial covering Analysis Tools we went into the purpose of using trendlines and touched on the equation powerpoint uses in creating the trendline based off of the provided Excel data. A trendline is simply what its name implies, a line that can be used to measure or predict expect growth or follow growth based on the data provided.
First have the data ready for your chart. The charts that can be best used with a trendline are column and line charts; however a line chart can best show the trendline. The example used will be for a fictional comedy show’s average TV ratings between 2002 and 2012.
It’s also worth noting that a line chart or column chart with significant peaks in valleys in data (such as the above example) are prime for trendlines as the different trendlines—except for Two Period Moving Average and Exponential Trendline—tend to just be a straight diagonal line.
The equation determining where it starts and end might be different, but the differences are barely noticeable once they’re on the chart. Next, go Layout under Chart Tools and click on Trendlines. This will give you a few lines to choose from. There are more as bar for the two mentioned above and a few others, the differences are minor.
In this tutorial, we will be picking the Linear Trendline.
As you can see, the trendline in the line chart starts just below the starting point and goes in a straight diagonal line to show the TV ratings in this example are expected to progress. In the example, there are peaks above the projected growth starting in 2008 and ending with 2010 before it dipping with 2011.
It should be noted that trendlines only predict the future of the data based on a particular formula and the data provided. Of course, it doesn’t take into account various things that could happen in a business such as economic stability, consumer demands and a company’s ability to supply, and other factors.
In short, a trendline is good to use for pre-compiled data over a particular period of time.