Exponential regression is a type of regression that can be used to model the following situations:
1. Exponential growth: Growth begins slowly and then accelerates rapidly without bound.
2. Exponential decay: Decay begins rapidly and then slows down to get closer and closer to zero.
The equation of an exponential regression model takes the following form:
y = abx
- y: The response variable
- x: The predictor variable
- a, b: The regression coefficients that describe the relationship between x and y
The following step-by-step example shows how to fit an exponential regression model to the following dataset on a TI-84 calculator:
Step 1: Enter the Data
First, we will enter the data values. Press STAT, then press EDIT. Then enter the x-values of the dataset in column L1 and the y-values in column L2:
Step 2: Fit the Exponential Regression Model
Next, we fill fit the exponential regression model.
Press Stat, then scroll over to CALC. Then scroll down to ExpReg and press ENTER twice.
The following results will be displayed:
Step 3: Interpret the Results
From the results we can see that the fitted exponential model is:
y = 1.727 * 1.651x
We can use this equation to predict the response variable, y, based on the value of the predictor variable, x. For example, if x = 4, then we would predict that y would be 12.83:
y = 1.727 * 1.6514 = 12.83
Bonus: Feel free to use this online Exponential Regression Calculator to automatically compute the exponential regression equation for a given predictor and response variable.
How to Perform Linear Regression on a TI-84 Calculator
How to Perform Quadratic Regression on a TI-84 Calculator
How to Create a Residual Plot on a TI-84 Calculator