A safety analyst wants to compare the variability in steering correction times for experienced and inexperienced drivers on three types of roads: paved, gravel, and dirt. The analyst records the time in seconds that each driver uses to make steering corrections on each type of road.
Interpret the results
In the output, both of the p-values are greater than the common significance level of 0.05. On the plot with the multiple comparison intervals, all the comparison intervals overlap. The p-values and the comparison intervals both indicate that the differences between the groups are not statistically significant.
Multiple comparisons and Levene’s methods are used.
These methods are valid for any continuous distribution.
|95% Bonferroni Confidence Intervals for Standard Deviations|
H₀: All variances are equal
H₁: At least one variance is different