A random sample of 160 car crashes are selected and categorized by age. The results are listed below.

The age distribution of drivers for the given categories is 18% for the under 26 group, 39% for the 26-45

group, 31% for the 45-65 group, and 12% for the group over 65. Calculate the chi-square test statistic 2

to test the claim that all ages have crash rates proportional to their driving rates.

Age Under 26 26 - 45 46 - 65 Over 65

Drivers 66 39 25 30