The White test is a statistical test to determine whether homoskedasticity exists in a data set. This test is based on the variance from the residual values. The TI Npsire is capable of computing this test even though it is not part of built-in functions, as the residual values can be recalled from regression tests. An example including multiple regression is shown below.
A scatter plot for visual inspection of heteroskedasticity.
In spreadsheet mode the calculation of the data set.
And in R.