Answer to Question #32116 in Statistics and Probability for Furber

Question

I need help understanding which PHStat and/or Excel stats plugin function to use for the following homework questions and also how to enter the values, check the boxes in the function window, etc. to get the information I need to answer my questions. Thank you very much for your guidance:

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 population, the mean number of cavities at a 6-month checkup is 1.73 (STD = 1.12).

a. Is this a one-or two-tailed test?
b. What are Ho and Ha for this study?
c. Compute Zobt
d. What is Zcv?
e. Should Ho be rejected? What should the researcher conclude?
f. Determine the 95% confidence interval for the population mean, based on the sample mean.