Question

How do I find an appropriate exponential model of given data points on a TI-83?

Answer 1

Getting the exact model is a kind of a trial and error process, but this is how you do it.

First, you input all your data points into your scatter plot (STAT`->`EDIT), and then turn on your plot (2ND`->`Y=`->`ENTER`->`ENTER). Once you have that done, go to your graph (Rightmost Key on the topmost row) and look at the points. Try and guess what model they look like:

graph{y=2(3)^x [-40, 40, -20, 20]}

Exponential Growth

graph{y=logx [-40, 40, -20, 20]}

Logarithmic

graph{y=2(3)^-x [-40, 40, -20, 20]}

Exponential Decay

Once you've got that, just go to your STAT key, scroll over to CALC, and select the correct model.

Hope that helped :)