Benign prostatic hyperplasia, quality of life. Benign prostatic hyperplasia is a noncancerous enlargement of the prostate gland that adversely affects the quality of life of millions of men. A study of a minimally invasive procedure for the treatment for this condition looked at pretreatment quality of life (QOL_BASE) and quality of life after 3 months on treatment (QOL_3MO). Table 11.4 lists data for 10 subjects chosen at random from this study

(a) Calculate differences in quality of life scores (DELTA) for each subject.

(b) Explore the differences with a stemplot. Discuss your exploration.

(c) Calculate the mean and standard deviation of the difference.
Then test the mean difference for statistical significance. Use a two-sided alternative hypothesis.q