Use the probability plot for the standardized residuals to determine the following:

- Whether the distribution assumption is appropriate
- Whether the assumption of equal shape (Weibull or exponential) or scale parameter (other distributions) is appropriate

The probability plot for the standardized residuals combines the data to calculate one fitted line, which helps you more easily determine whether the plotted points follow the fitted line closely. If the plotted points follow the fitted line closely, then the assumptions are appropriate. If the plotted points do not follow the fitted line, then either or both assumptions might be violated.

For the compressor case data, the plotted points follow the fitted line. Therefore, the plot suggests that the assumptions are appropriate.