The producers of a new toothpaste claim that it prevents more cavities than other brands of toothpaste. A random sample of 60 people used the new toothpaste for 6 months. The mean number of cavities at their next check up is 1.5. In the general population, the mean number of cavities at a 6 month check up is 1.73. a. Is this a one or two tailed test