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. Suppose we wish to understand if a particular treatment for prostate cancer de

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Question

. Suppose we wish to understand if a particular treatment for prostate cancer decreases the prostate specific antigen (PSA) concentration after 3 weeks. We have measures of PSA before and after treatment. (a) What are the null and alternate hypotheses for this case? (b) Suppose we measure the change in PSA concentration in 15 subjects and find that there is a mean decrease of 5 ng/ml and sample standard deviation of 10 ng/ml. Can we reject the null hypothesis at an = 0.05 level? (c) Suppose we wished to establish if there is any change in PSA concentration. What are the null and alternate hypotheses for this case? (d) Using the same data from part (b), determine if we can reject the null hypothesis at an = 0.05 level. (e) Comment on the advantages and disadvantages of these two tests.

Explanation / Answer

. Suppose we wish to understand if a particular treatment for prostate cancer decreases the prostate specific antigen (PSA) concentration after 3 weeks. We have measures of PSA before and after treatment. (a) What are the null and alternate hypotheses for this case? (b) Suppose we measure the change in PSA concentration in 15 subjects and find that there is a mean decrease of 5 ng/ml and sample standard deviation of 10 ng/ml. Can we reject the null hypothesis at an = 0.05 level? (c) Suppose we wished to establish if there is any change in PSA concentration. What are the null and alternate hypotheses for this case? (d) Using the same data from part (b), determine if we can reject the null hypothesis at an = 0.05 level. (e) Comment on the advantages and disadvantages of these two tests.