Company officials are concerned about the length of time a particular drug retains its potency. A random sample (sample 1) of 10 bottles of the product is drawn from current production and analyzed for potency. A second sample (sample 2) is obtained, stored for 1 year, and then analyzed. The readings obtained are as follows:
The data are analyzed by a standard program package (SAS). The relevant output is shown here:
a. What is the research hypothesis?
b. What are the values of the t and t statistics? Why are they equal for this data set?
c. What are the p-values for t and t statistics? Why are they different?
d. Are the conclusions concerning the research hypothesis the same for the two tests if we use a = .05?
e. Which test, t or t, is more appropriate for this data set?