At the end of the 19th Century, it was widely believed that criminal tendencies might also be expressed in physical characteristics that were distinguishable from the physical characteristics of noncriminal classes. Macdonell (1901) compared the length (cm) of the left middle index finger (XX) and the height in inches (YY) for 20 criminals. Macdonell then compares these measurements of the criminals to those of Cambridge men (presumed to come from a different class in society).

XX

YY

10.7

60.6

10.2

63.9

10.9

61.8

10.6

61.2

12.9

62.7

10.1

66.1

12.8

63.7

13.4

66.7

13.8

66.5

12.4

69.3

14.2

66

10.3

67.1

11.1

67.9

13.4

72.3

11.8

71

13.4

74.3

14.8

72.3

14.7

73.9

14.9

72.8

17.6

74

n=20,i=1nxi=254,i=1nx2i=3,301.92,i=1nyi=1,354.1,i=1nxiyi=17,312.89,i=1n(yiy)2=218.444n=20,i=1nxi=254,i=1nxi2=3,301.92,i=1nyi=1,354.1,i=1nxiyi=17,312.89,i=1nyiy^2=218.444

Find the correleration coefficient r.