Insurance companies recommend a personal umbrella policy for most customers, even if they already have a home and an automobile policy. Basic liability coverage may not be adequate as lawsuits become...

Insurance companies recommend a personal umbrella policy for most customers, even if they already have a home and an automobile policy. Basic liability coverage may not be adequate as lawsuits become more common and jury awards escalate. A random sample of adults with umbrella policies was obtained, and the amount of coverage was recorded for each (in millions of dollars). Assume the underlying distribution of umbrella coverage amounts is continuous. Use the sign test with a = 0.05 to determine whether there is any evidence that the median coverage amount is different from $2.00 million.

Recent research suggests that exposure to disinfection by-products (DBPs) in swimming pools may increase the risk of some cancers.38 A study was conducted to determine whether exposure to DBPs in pool water increased toxic biomarkers. A random sample of adults was obtained and the concentration of four trihalomethanes (THMs, in m/m3 ) in exhaled breath was measured before and one hour after swimming. Assume that the distribution of pairwise differences is continuous and symmetric. Use the Wilcoxon signed-rank test with a = 0.05 to determine whether there is any evidence that the median THM concentration is greater after swimming.