Do poorer people tend to have shorter lives than richer people? Two researchers ranked all counties in the United States by their poverty level and then divided them into 20 groups, each representing approximately 5% of the overall U.S. population. The bottom 5% were the least impoverished (wealthiest) and top 5% (the 100th percentile) the most impoverished. Life expectancies at birth for each of the 20 groups were calculated based on life tables. The table contains the data poverty percentiles (higher percentiles correspond to greater poverty) and life expectancies at birth (in years) in 2010 for males in the 20 groups.

Percentile rank5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90

95

100

Life expectancy of males79

79

78

77.5

77.5

77.5

77

76.5

77

77

76.5

76

76

77

76.5

75

75.5

74

74

73

Find the correlation