A study was done of 137 young adult males who had been treated for substance abuse. The study compared their yearly rates of traffic accidents before treatment and after treatment. For the pre-treatment group, the mean accident rate was 0.123, with a standard deviation of 0.167. For the post-treatment group, the mean accident rate was 0.068, with a standard deviation of 0.223 (based on data from "Does Treatment for Substance Abuse Improve Driving Safety? A Preliminary Evaluation," by Mann et al., Addiction Research Foundation). At the 0.05 significance level, test the claim that the standard deviation for the post-treatment group is greater than that for the pre-treatment group.