Pain tolerance study. A study published in Psychosomatic Medicine (Mar./Apr. 2001) explored the relationship between reported severity of pain and actual pain tolerance in 337 patients who suffer from chronic pain. Each patient reported his/her severity of chronic pain on a seven-point scale 11 = no pain, 7 = extreme pain2. To obtain a pain tolerance level, a tourniquet was applied to the arm of each patient and twisted. The maximum pain level tolerated was measured on a quantitative scale.

a. According to the researchers, “Correlational analysis revealed a small but significant inverse relationship between [actual] pain tolerance and the reported severity of chronic pain.” On the basis of this statement, is the value of r for the 337 patients positive or negative?

b. Suppose that the result reported in part a is significant at a = .05. Find the approximate value of r for the sample of 337 patients.