A pharmaceutical company is planning to market a drug that is supposed to help reduce blood pressure. The company claims that if the drug is taken properly, the amount of blood pressure decrease will be normally distributed with a mean equal to 10 points on the diastolic reading and a standard deviation equal to 4.0. One hundred patients were administered the drug, and data were collected showing the reduction in blood pressure at the end of the test period. The data are located in the file labeled Blood Pressure.
a. Using a goodness-of-fit test and a significance level equal to 0.05, what conclusion should be reached with respect to the distribution of diastolic blood pressure reduction? Discuss.
b. Conduct a hypothesis test to determine if the standard deviation for this population could be considered to be 4.0. Use a significance level of 0.10.
c. Given the results of the two tests in parts a and b, is it appropriate to construct a confidence interval based on a normal distribution with a population standard deviation of 4.0? Explain your answer.
d. If appropriate, construct a 99% confidence interval for the mean reduction in blood pressure. Based on this confidence interval, does an average diastolic loss of 10 seem reasonable for this procedure? Explain your reasoning.