2 the producers of a new toothpaste claim that it

Question

2.  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 checkup is 1.5. In the general poplation, the mean number of cavities at a 6 month checkup is 1.73  (s.d. = 1.12).

 

1. Is this a one or two tailed test?
2. What are the Ho and Ha for this study?
3. Compute z_obt+
4. What is Z_cv ?
5. Should Ho be rejected? What should the researcher conclude?
6. Determine the 95% confidence interval for the population mean, based on the sample mean.