# What does the notation like 8.6e-28 mean? What is the ‘e’ for?

I have a problem with the interpretation of a test result in which the p-value is 8.6e-28. How should it be interpreted? What is the e for?

Specifically, I used White’s Test for the homoscedasticity assumption of a linear regression:

White's general test statistic :  150.0535  Chi-sq( 9)  P-value =  8.6e-28


The e is standard scientific notation for powers of $10$: 8.6e-28 means $8.6 \cdot 10^{-28}$.
The White test tests for heteroscedasticity of a variable’s distribution, most commonly in the residuals of your regression. A significant result indicates that your data are significantly heteroscedastic, and thus the assumption of homoscedasticity in the regression residuals is violated. In your case the data violate the assumption of homoscedasticity, as your $p$ value is $8.6 \cdot 10^{-28}$. The e is standard scientific notation for powers of $10$.