Page 86 - Statistics for Dummies

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Part II: Number-Crunching Basics
Table 5-1 (continued)
%
Females
Males
%
Age
Both
%
Group
Sexes
45–49
7.09
10,677,847
21,761,391
50–54
11,083,544
7.05
7.13
55–59
18,975,026
6.28
6.08
9,770,360
6.18
9,204,666
15,811,923
5.29
8,234,990
5.15
7,576,933
5.00
60–64
11,784,320
65–69
6,273,156
3.84
4.03
5,511,164
3.64
4,925,521
4,082,226
2.93
70–74
2.70
9,007,747
3.17
2.08
2.39
3,149,236
7,325,528
75–79
2.68
4,176,292
1.52
2,298,260
2.27
80–84
3,524,074
5,822,334
1.90
1.54
2,395,498
0.84
1,266,899
3,662,397
1.19
85–89
1,077,381
0.28
0.49
0.69
1,502,263
90–94
424,882
401,977
0.05
319,842
95–99 22,831,092 7.44 11,295,524 7.46 11,535,568 7.42
82,135
0.21
0.13
100+ 64,024 0.02 8,758 0.01 55,266 0.04
Total 307,006,550 100.00 151,449,490 100.00 155,557,060 100.00
You can examine many different facets of the U.S. population by looking at and
working with different numbers from Table 5-1. For example, looking at gender,
you notice that women slightly outnumber men — the population in 2009 was
50.67% female (divide total number of females by total population size and mul-
tiply by 100%) and 49.33% male (divide total number of males by total popula-
tion size and multiply by 100%). You can also look at age: The percentage of the
entire population that is under 5 years old was 6.94% (divide the total number
under age 5 by the total population size and multiply by 100%). The largest
group belongs to the 45–49 year olds, who made up 7.44% of the population.
Next, you can explore a possible relationship between gender and age by
comparing various parts of the table. You can compare, for example, the per-
centage of females to males in the 80-and-over age group. Because these data
are reported in 5-year increments, you have to do a little math in order to
get your answer, though. The percentage of the population that’s female and
aged 80 and above (looking at column 7 of Table 5-1) is 2.27% + 1.54% + 0.69%
+ 0.21% + 0.04% = 4.75%. The percentage of males aged 80 and over (looking
at column 5 of Table 5-1) is 1.52% + 0.84% + 0.28% + 0.05% + 0.01% = 2.70%.
This shows that the 80-and-over age group for the females is about 76% larger
than the males (because [4.75 – 2.70] ÷ 2.70 = 0.76).
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