X on Y Regression Line
Equation of the Regression Line
The x on y regression line, also known as the inverse regression line, is a statistical tool used to predict the value of an independent variable (x) based on a given dependent variable (y). This is in contrast to the more commonly used y on x regression line, which predicts y based on x.
The equation for the x on y regression line is:
$x = a + by$
Where:
- $x$ is the independent variable
- $y$ is the dependent variable
- $a$ is the x-intercept
- $b$ is the slope of the line
It's important to remember that the x on y regression line is different from the y on x regression line. They will have different equations and slopes, except in the case of perfect correlation (r = 1 or r = -1).
NoteThere are two ways to calculate the gradient of a regression line
- You can either plot out the points on an axes and then draw out a line of best fit
- Put the values into the Statistics section of the GDC and then copy the data very carefully onto your exam paper
