Refer to Exercise 7.27. How would your inference procedures change if preparation A was...

Refer to Exercise 7.27. How would your inference procedures change if preparation A was an old product that had been on the market a number of years and preparation B was a new product, and we wanted to determine whether people would continue to use B a longer time in comparison to preparation A?

REFERENCE:

7.27 : Sales from weight-reducing agents marketed in the United States represent sizable amounts of income for many of the companies that manufacture these products. Psychological as well as physical effects often contribute to how well a person responds to the recommended therapy. Consider a comparison of two weight-reducing agents, A and B. In particular, consider the length of time people remain on the therapy. A total of 26 overweight males, matched as closely as possible physically, were randomly divided into two groups. Those in group 1 received preparation A and those assigned to group 2 received preparation B. The data are given here (in days).

Compare the lengths of times that people remain on the two therapies. Make sure to include all relevant plots, tests, confidence intervals, and a written conclusion concerning the two therapies.