statistics

profilesary-2h51
project__sample_1.docx

Local Human Longevity: Female vs. Male

Introduction

It is often heard that female and males do not share the same life expectancy. According to the National Vital Statistics Reports, the average life expectancy for a female is 80.2 years and for a male 75.1 years, as of 2006. To test how these number correlate with the local distribution, I have assembled data consisting of 25 female’s age at death and 25 male’s age at death from a local cemetery located in Hammond, Indiana. All deceased passed within the years 2000-2010.

Data

MALES

Death within 2000-2010

Birth year

Death year

Age at death

1920

2006

86

1946

2007

61

1957

2006

48

1917

2006

89

1929

2001

72

1911

2010

99

1913

2004

91

1916

2005

89

1923

2001

78

1913

2004

89

1922

2001

79

1924

2009

85

1909

2004

95

1924

2004

80

1949

2004

55

1939

2003

64

1959

2006

47

1930

2010

80

1918

2005

87

1924

2009

85

1919

2002

83

1941

2003

62

1918

2007

89

1922

2001

79

1913

2007

94

Table 1

FEMALES

2000-2010 death year

Birth year

Death year

Age at death

1913

2008

95

1917

2010

93

1911

2004

93

1934

2007

73

1914

2001

87

1910

2001

91

1906

2003

97

1918

2000

82

1918

2011

93

1922

2001

79

1922

2003

81

1913

2003

90

1917

2008

91

1935

2003

68

1910

2001

91

1949

2004

55

1916

2006

90

1911

2010

99

1919

2005

86

1921

2002

81

1919

2010

91

1913

2006

93

1919

2002

83

1913

2002

89

1913

2002

89

Table 2

Histograms below dimply the frequency distribution of the age at the time of death for both male and female in Hammond, IN.

Numerical Summary are provided in the table 3 and table 4

Females Summary

Minimum

55

1st Quartile

70

Median

90

3rd Quartile

93

Max

99

Mean

86.4

Males Summary

Minimum

47

1st Quartile

70

Median

84

3rd Quartile

89

Max

99

Mean

78.625

Table 3 Table 4

We would like to test whether there is a difference in the survival time based on the gender. We will test the following hypothesis. Let denote the mean life expectancy for male and female respectively. We will test the following hypothesis.

Below is the computer output from the data analysis

> t.test(Female, Male)

Welch Two Sample t-test

data: Female and Male

t = 2.2148, df = 42.008, p-value = 0.03225

alternative hypothesis: true difference in means is not equal to 0

95 percent confidence interval:

0.6891875 14.8308125

sample estimates:

mean of x mean of y

86.40 78.64

Decision: Since p-value=0.03225 is less than standard value 0.05 level of significance we reject the null hypothesis and conclude that there is a significance difference in the life expectancy of male and female. Also note that 95% confidence interval for the difference in the life expectancy is (0.69, 14.83).

Discussion

With the relatively small sample size it is apparent the life expectancies do differ. The female longevity average was 86.4 and the male longevity average was 78.64, giving the difference of 7.76 years.

Additionally, with hypothesis testing, it was significant that females do not have the same life expectancy as males (p=0.03225).

References Arias, E. (2010). United States Life Tables, 2006. National Vital Statistics Reports, 58(21), 1-40.

Male Survivorship 2000-2010

lx 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 1 1 1 1 1 1 1 1 1 1 0.96000000000000063 0.96000000000000063 0.92 0.76000000000000123 0.76000000000000123 0.72000000000000064 0.6800000000000006 0.44000000000000006 0.2 4.0000000000000022E-2 0

Age (years)

Proportion surviving (lx)

Female Survivorship 2000-2010

lx 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 1 1 1 1 1 1 1 1 1 1 1 1 0.96000000000000063 0.96000000000000063 0.92 0.88 0.84000000000000064 0.68 0.52 0.12000000000000002 0

Age (years)

Proportion surviving (lx)

Female

Male

a

Female

Male

H

H

m

m

m

m

¹

=

:

:

0

Histogram of Female

Age

Frequency

5060708090100

0

2

4

6

8

10

Histogram of Male

Age

Frequency

405060708090100

0

2

4

6

8

FemaleMale

50

60

70

80

90

100

Boxplot of the life expectancy

Female

Male

and

m

m