How do i calculate the standard deviation from these results

its about life expectancy over fertility rate anyway how do i calculate the standard deviation from these results?


Life expectancy Fertility rate
82.25 /1.21
81.81 /1.78
81.07 /1.46
80.9 /1.89
80.05 /1.91
79.78 /1.4
78.37 /2.06
77.7 /1.88
77.41 /1.48
72.66 /2.97
68.58 /1.28
68.51 /1.87
68.31 /2.21
66.8 /2.62
62.39 /3.41
59.48 /4.19
58.05 /2.5
53.4 /7.6
52.36 /5.98
52.19 /2.49
49.33 /2.3
48.7 /4.51
48.66 /3.11
47.56 /4.73
45.02 /5.39

Define a new variable I = LE/FR.

You'll get 67.97520661, 45.96067416, ..., 8.352504638.

You've 3 outliers = 7.026315789 (obs 18), 8.352504638 (obs 25) and 8.755852843 (obs 19)

Apply the formula for SD

SD = sqrt((1/24)*∑(i - Imean)^2)

You'll get SD = 13.1388847

Your work values are:

The SAS System

Obs LE FR i

1 82.25 1.21 67.9752
2 81.81 1.78 45.9607
3 81.07 1.46 55.5274
4 80.90 1.89 42.8042
5 80.05 1.91 41.9110
6 79.78 1.40 56.9857
7 78.37 2.06 38.0437
8 77.70 1.88 41.3298
9 77.41 1.48 52.3041
10 72.66 2.97 24.4646
11 68.58 1.28 53.5781
12 68.51 1.87 36.6364
13 68.31 2.21 30.9095
14 66.80 2.62 25.4962