# How do you extrapolate using a linear regression line?

##### 1 Answer

Mar 14, 2018

When we use regression line to predict a point whose x-value is outside the range of x-values of training data, it is called extrapolation.

In order to (deliberately) extrapolate we just use the regression line to predict values that are far from training data.

Note that extrapolation does not give reliable predictions because the regression line may not be valid outside the training data range.