A recent study investigated the possibility of using moving cars to measure the amount and intensity of rainfall, rather than traditional rain gauges.44 A random sample of automobiles was selected,...

A recent study investigated the possibility of using moving cars to measure the amount and intensity of rainfall, rather than traditional rain gauges.44 A random sample of automobiles was selected, and each was equipped with an automatic wiper system. Each car was subject to 10–15 minutes of rain in a controlled laboratory setting. The wiper frequency (x, w/min) and the rain intensity ( y, mm/h) were recorded for each. Compute Spearman’s rank correlation coefficient. Use this value to explain the relationship between wiper frequency and rain intensity and whether you believe wiper frequency might be used to predict rainfall total.

The traditional method for people to test their blood glucose level is to prick a finger with a short needle, place a drop of blood on a test strip, and then use a special measuring device. The process can be painful. A group of scientists has developed a noninvasive, painless approach to measuring glucose level using infrared laser light. A random sample of healthy adults was obtained.

The glucose level was measured in each using the traditional method and the laser light approach (both measurements in milligrams per deciliter). Assume the underlying distribution of pairwise differences is continuous and symmetric. GLUCOSE

a. Use the Wilcoxon signed-rank test to determine whether there is any evidence that the median glucose levels are different for the two procedures. Use a = 0.01.

b. Using your answer in part (a), do you believe the new approach is accurate and should be recommended for people with diabetes who test their glucose level regularly? Justify your answer.