This tutorial explains how to calculate the value of Relative Standard Deviation.
The Weight of a group of 5 persons are 45,50,55,60,67. Calculate the standard deviation of those persons.
Mean Values (X) = 45,50,55,60,67 N = 5
Relative standard deviation (RSD)
Let us first calculate the value of x,
x | = (45+50+55+60+67)/ 5 |
= 277/5 | |
= 55.4 |
Calculate the value of x, x-x, x-x2.
x | x-x | x-x2 |
---|---|---|
45 | -10.4 | 108.16 |
50 | -5.4 | 29.16 |
55 | -0.4 | 0.16 |
60 | 4.6 | 21.16 |
67 | 11.6 | 134.56 |
Now, let us calculate the value of Standard Deviation(S).
S =√(Σ(x-x)2/N-1)S =√(293.20000000000005)/4 = 8.56
Relative Standard Deviation Calculation:
RSD = S*100 / x=(8.56*100)/55.4 = 15.45
Standard Deviation = 8.56 Relative Standard Deviation = 15.45