TI-84 Plus CE field manual for IB Math
Exponential regression
Fit y=a⋅bx to paired data and read the fitted parameters.
Fit an exponential model to (0,5),(1,8),(2,11),(3,20),(4,31).
Turn diagnostics on so the calculator shows r: press to open the catalog, choose DiagnosticOn, and press .
Open the list editor with → 1: Edit. Enter the x-values 0, 1, 2, 3, 4 in L1 and the y-values 5, 8, 11, 20, 31 in L2.
Run exponential regression: press , move right to CALC, then press for 0:ExpReg. Set Xlist = L1 (type L1 with ) and Ylist = L2 (type L2 with ); leave FreqList and Store RegEQ blank, clearing them with if anything is there. Then choose Calculate.
The calculator uses the form y=a⋅bx, so the model is y≈4.90(1.58)x, with r≈0.997.
Your turn
Work each one on your calculator, then check the answer.
- 1
Fit an exponential model y=a⋅bx to (0,4), (1,6), (2,10), (3,15).
- 2
Fit an exponential model to the (noisy) data (0,3.1), (1,4.1), (2,6.0), (3,8.1).
- 3
Fit an exponential model to (0,80), (1,63), (2,52), (3,41), (4,33).