Automobile insurance is much more expensive for teenage drivers than for older drivers. To justify this cost difference, insurance companies claim that the younger drivers are much more likely to be involved in costly accidents. To test this claim, a researcher obtains information about registered drivers from the department of motor vehicles and selects a sample of n=300 accident reports from the police department. The motor vehicle department reports the percentage of registered drivers in each age category as follows: 16% are under the age 20; 28% are 20 to 29 years old; and 56% are 30 or older. The number of accident reports for each age group is as follows:

Under Age Age 30

Age 20 20-29 or older

68 92 140

68 92 140