2 Replies Latest reply: Mar 11, 2011 6:21 PM by Barry
Asclepius37 Level 1 Level 1 (0 points)
I'm not sure if this is well-known or has been answered elsewhere already, but multiple Google searches have not shown this solution on how to create a line of best fit in Numbers '09 (there is another method that involves drawing a line yourself, but this is much easier and more accurate).

I stumbled across this trying the above self-draw technique and got so excited I wanted to post the technique. So here is what you do:

1) Type out your X and Y data

2) Select the data and select Charts, then select the Scatter Plot

3) Open up Inspector and select the Chart tab

4) Select the "Series" tab below the picture of the Scatter Plot and the "Chart Colors..." button

5) At the bottom of the Inspector window, open the "Advanced" arrow

6) Select the "Trendline" tab and select the "Linear" trendline from the drop-down bar

That's it! You can even select the options to show the line equation or the R-squared value!

Here is a picture of the selected options and what your graph should look like (check that nice R-squared value!).


I hope this helps and hope it moves up to the top of the Google search page for this feature.

MacBook Pro, Mac OS X (10.6.6), -
  • Badunit Level 6 Level 6 (11,440 points)
    It is covered in the Numbers User's Guide, available in the Help menu. A search of the guide for the word "trendline" will take you right to the section on how to create them. The User's Guide is usually the best place to start looking, not Google.
  • Barry Level 7 Level 7 (29,600 points)
    Hi Asclepius37,

    Why not just search "trend" or "trendline" in the Numbers '09 User Guide?

    That would take you to page 149 of the guide and the article "Showing Trendlines in Charts," which lists a set of instructions very similar to those in your post.

    The Numbers '09 User Guide and the iWork Formulas and Functions User Guide are searchable pdf files, and may both be downloaded through kinks in the Help menu in Numbers. Both are excellent resources to have on hand.


    PS: Searching "best fit" will return zero results, but "best" or "best-fit" will get you to the same article.