How to Find the Correlation Coefficient on a TI-84 Calculator
There are multiple methods to calculate the Correlation Coefficient. The TI-84 has a built-in function called LinReg(ax+b) to calculate it. So, we’ll discuss that method to easily find it without doing any extra steps.
Let’s break down this method into 3 easy steps:
Step 1: Turn On Diagnostics
Before your TI-84 will show r, you have to turn diagnostics ON.
- Press [2nd], then [0] to open the Catalog
- Scroll down to DiagnosticOn
- Press [ENTER], then [ENTER] again
- You’ll see Done on the screen
This only needs to be done once, unless your calculator is reset.
Step 2: Enter Data into Lists
- Press [STAT], then choose 1: Edit
- Enter your x-values (independent variable) into L1
- Enter your y-values (dependent variable) into L2
- Make sure each x-value has a matching y-value
Example:
L1 = {2, 4, 6, 8, 10}
L2 = {1, 3, 5, 7, 9}
Step 3: Run the Linear Regression
- Press [STAT], then scroll to CALC using the right arrow
- Choose 4: LinReg(ax+b)
- You should see:
LinReg(ax+b) L1, L2
If not, enter it manually:
LinReg(ax+b) L1, L2
(Use [2nd] + 1 for L1, [2nd] + 2 for L2) - Press [ENTER] to calculate
The calculator will show:
- a (slope)
- b (y-intercept)
- r (correlation coefficient)
- r² (coefficient of determination)
Try calculating correlation coefficients yourself using our online TI-84 Plus calculator with built-in stats functions. Apply the above method and practice it.
Correlation Coefficient (r):
A number between -1 and 1 that measures the strength and direction of a linear relationship between two variables.
- +1 = perfect positive correlation
- -1 = perfect negative correlation
- 0 = no linear correlation
Coefficient of Determination (r²):
The square of the correlation coefficient (r²). It tells you the percentage of variation in one variable that can be explained by its relationship with the other variable.
- Ranges from 0 to 1
- Example: r² = 0.85 means 85% of the variation is explained by the model.