Two counties in Pennsylvania handle delinquent property-tax payments in different manners. The first county has very strict regulations that include interest on the unpaid balance and eventually...

Two counties in Pennsylvania handle delinquent property-tax payments in different manners. The first county has very strict regulations that include interest on the unpaid balance and eventually property seizure. The second county uses a more personal touch. Someone calls or visits the property owner to discuss the overdue bill and, if necessary, a payment schedule is created. A random sample of delinquent payments in each county was obtained, and the data were paired according to the size of the original property-tax bill. The amount of time (in months) until full payment was made was recorded for each property. Assume the distribution of pairwise differences is continuous and symmetric. Use the Wilcoxon signed-rank test to determine whether there is any evidence of a difference in median collection time due to the method of handling delinquent payments. Use a = 0.10, and find the p value associated with this test.

CBC News recently reported that close to 8 million acres of farmland in China is too polluted to use for growing food. There is a high concentration of heavy metals and other chemicals in the soil, and some of these pollutants have already made it into the food chain through rice and other crops. Cadmium is a carcinogenic metal that can cause kidney damage, is absorbed by rice, and is of particular concern.16 A random sample of farmland near Guangzhou was identified, and samples of soil were taken from each. The concentration of cadmium in each sample was measured. Assume that the distribution of the concentration of cadmium is continuous. Use the Wilcoxon signed-rank test to determine whether there is any evidence that the median cadmium concentration is greater than 1 ppm. Use a = 0.05 and find the p value for this test.