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Line of Best Fit

  • Classroom Resources / Illuminations

    Line of Best Fit

    Grade:

    This activity allows the user to enter a set of data, plot the data on a coordinate grid, and determine the equation for a line of best fit.

    This interactive is optimized for your desktop and tablet.

    Activity

    Instructions

    • Plot points by clicking anywhere on the grid, or plot a set of points by entering a pair of coordinates in the text box and clicking Add Point. 
    • LineOfBestFit IMAGE RemovePointButtonCheck the Remove Points box and click on any point to remove it. You can also click‑and‑drag any point to change its location.
    • When you check the box for Show Guess, a purple line will appear on the grid. Drag the purple dots to approximate a line of best fit visually. An equation of this line will appear to the right. A slope and y-intercept can also be entered to change the line of best fit.
    • When you check the box for Show Line of Best Fit, the area least-squares regression line will be displayed. An equation of this line and the correlation coefficient (r) will appear.
    • The grid can be zoomed in and out as more points are added. Use the + and –Magnifying Glass to zoom.
    • LineOfBestFit IMAGE MoveGraphButtonTo see a different portion of the grid, highlight the Move Graph box and use the mouse to drag the graph around.
    • LineOfBestFit IMAGE ResetOrFitButtonYou can reset the original parameters for the graph or use the Zoom to Fit box to have the graph automatically select parameters that will show all your points optimally.