Data Coding/Examples/Arbitrary Example 1
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Examples of Data Coding
Let us wish to calculate the mean and standard deviation of the numbers:
- $179 \cdotp 385$
- $179 \cdotp 387$
- $179 \cdotp 392$
We may multiply by $1000$ and then subtract $179 \, 387$ (which is the same as adding $-179 \, 387$) to give:
- $-2$
- $0$
- $5$
The mean is:
- $\dfrac {-2 + 0 + 5} 3 = 1$
The standard deviation is:
- $\sqrt {\dfrac {\paren {-2 - 1}^2 + \paren {0 - 1}^2 + {5 - 1}^2} 3} = \sqrt {\dfrac {26} 3} = 2 \cdotp 94$
Adding $179 \, 387$ to $1$ and multiplying by $\dfrac 1 {1000}$ gives the mean as:
- $179 \cdotp 388$
Multiplying $2 \cdotp 94$ by $\dfrac 1 {1000}$ gives the standard deviation as:
- $0 \cdotp 002 \, 94$
Sources
- 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): data coding
- 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): data coding