A random sample of 160 car crashes are selected and categorized by age. The results are listed below. The age distribution of dr
ivers 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 χ to test the claim that all ages have crash rates proportional to their driving rates.
1. Under 26 = 66 drivers
2. 26-45 = 39 drivers
3. 46-65 = 25 drivers
4. Over 65 = 30 drivers
Given that 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.
The difference in fixed charge is $20; the difference in mileage charge is $0.50 per mile. So it will take $20/$0.50 = 40 miles for the extra mileage cost to eat up the savings in fixed cost. At that mileage, both companies will charge the same amount: