The growth factor pleiotrophin is associated with cancer progression in humans. In an attempt to monitor the growth of tumors, doctors measured serum pleiotrophin levels in patients with pancreatic cancer and in a control group of patients. They found that only 2 of 28 control patients had serum levels more than two standard deviations above the control group mean, whereas 20 of 41 cancer patients had serum levels this high. Use Fisher's exact test to determine whether a discrepancy this large (2 of 28 versus 20 of 41) is likely to happen by chance. Use a directional alternative and let α = 0.05.