You have to first enter these values into a table. You find that table on your calculator at "stat" then "edit". In L1, enter all the x values, hitting "enter" after each entry. Then arrow over to L2 and enter all the y values. When you are done, hit "stat" again, then "calc" and choose 4 LinReg, then hit enter. If you do not see the r and r-squared values, then you need to turn on your diagnostics. To do this, hit 2nd, then 0 to pull up your catalog. Hit the button and that brings up all the D's in your catalog. Arrow down til you see "DiagnosticsOn" and hit enter. Then hit enter again. Go back to "stat", "calc", "4 LinReg" and hit either enter or calculate (it depends upon which calculator you have. The TI 83 just needs the "enter" button, while the TI84 family requires that you scroll down to the word "calculate" and hit "enter"). Then when the linear regression equation comes up, you will see underneath it both the correlation coefficient (r) and the coefficient of determination (r-squared). You should see that your r value is .84 for this data set. Just so you know, r can be negative, but r-squared never will be.
