To calculate an exponential regression, follow these steps.

Data for this example:
L1: {0,1,2,3,4,5,6,7}
L2: {200,118,70,40,25,15,8,4}

1. Press m and press the right arrow key › to highlight CALC.
2. Press the down arrow key ≥ to option B: ExpReg or option C: eBaseReg (for base e regression model) and press =.
3. Make sure your XLIST and YLIST are in the wizard as expected, use the store RegEQ entry line to store the equation to the function editor list by giving the desired y-variable.
4. Select the softkey for CALCULATE by pressing d or f.