Skill Level: Basic (No previous Excel knowledge needed to complete this instructable.)
Time requirement - 5 minutes.
Excel version: Microsoft Windows Excel 2013 (Other versions are similar and you should be able to follow this instructable)
This Instructable will give step by step instructions on how to create a chart, or graph, in Microsoft Excel and then how to find an equation for the graph's trend line.
Step 1: Organize Your Data So That Each Set Is in Its Own Column.
Thinking about a graph determine what set of data you want on your X axis and what data you want on your Y axis.
To make things easier label the first row of your X set of data with an X and your Y set of data with a Y. (If your data takes up the top row of your spreadsheet you can right click on the first row and hit insert.)
Step 2: Set Your Data So That the X Set of Data Is to the Column Directly Left of the Y Data.
Step 3: Highlight Both Your X and Y Data.
Step 4: Find Insert on in the Task Bar Towards the Top of Excel.
Step 5: Find the Recommended Charts Section and Select the Type Scatter. (You Can Use Other Types But You Can’t Create Trend Lines for the Other Types.)
After selecting your chart you should see the chart pop up somewhere on your spreadsheet.
Step 6: Once Your Graph Has Been Made You Can Edit the Title of the Graph and Axis.
To change the title of your graph double click on the current title that should be located at the top of your graph. You should see four blue dots surrounding the title if you have selected it correctly.
If you don’t see any graph title, or if you want to add axis titles to your graph you need to select your graph, a plus sign should appear to the top right of your graph, click on the plus sign and select the axis titles option.
Step 7: To Add a Trend Line to Your Graph, Left Click on the Line of the Graph. You Should See a Bunch of Blue Dots Show Up on Your Graphs Line If You Have Selected It Correctly. (See the Image for Reference.)
Step 8: Once the Line Is Selected Right Click on It and Select Add Trend Line From the Menu That Pops Up.
Step 9: A Menu Should Open Up on the Right Side of Excel, You Then Need to Find the Right Form for Your Line.
Step 10: When You Select a Trend Line a New Dashed Line Should Appear on Your Graph. the Pre-selected Line Might Not Be Correct (See Picture)
Try different trend line options until the trend line most closely fits your non dashed line. (You might not be able to see the dashed line anymore, but that is ok because that means the trend line fits your data perfectly). A good trend line will be very similar to the curve of your graph.