In 2010, the total number of prescriptions sold in the United States was 3,676,000. (Source: National Association of Drug Store Chains.) The sales manager of a chain of drug stores wanted to determine whether changes in where the prescriptions were filled had changed. A survey of prescriptions was undertaken in 1995, 2000, 2005, and 2010. The year and type of each prescription were recorded using the codes that follow. Determine whether there are differences among the years.
1. Traditional chain store
2. Independent drug store
3. Mass merchant
4. Supermarket
5. Mail order