The TI-84 Plus is one of a series of graphic calculators made by Texas Instruments. In addition to performing basic math functions, such as multiplication and linear graphing, the TI-84 Plus can find solutions for problems in algebra, calculus, physics and geometry. It can also calculate statistics functions, including finding the correlation coefficient and coefficient of determination of a data set.
Set up your calculator to allow diagnostics. Press the “2nd” key, then “Catalog.” Scroll down to “DiaGnosticOn” and press “Enter.” Wait until your screen displays the words “DiaGnosticOn,” then press “Enter” again.
Input your data set. Press the “Stat” key, navigate to the “Edit” option, then press “Enter.” Input your x values under the L1 section. Input your y values under the L2 section.
Press the “Stat” key, navigate to the “Calc” option, scroll down to the option labeled “LinReg,” then press “Enter.” You should now see the formula for a linear regression line on your home screen. Press “Enter.”
Wait for your calculator to display the values for the linear regression line. The number beside the value marked “r” is your correlation coefficient. The number beside the value marked “r^2” is your coefficient of determination.