Coding
Coding
- In coding, we change the data set in some way to make it easier to process.
- Linear coding involves \(+, -, \times, \div\).
Rules of coding
- Addition and subtraction have no effect on the standard deviation, however they do have an effect on the mean.
— - E.G. If we have \(y=x+10\), the mean will be increased by 10, but since all the values have been increased by a linear amount, there is no change to the standard deviation.
— - However. multiplication and division do have an effect on the standard deviation as well as the mean.
— - E.G. If we have \(y=3x\), the mean will be 3 times bigger than before and the standard devation will be 3 times more spread out than before.
— - Finally, if we have multiple operations, e.g. \(y=2x-5\), the multiplication takes effect on the standard deviation but the subtraction has no effect. This would mean the standard deviation would be the same as \(y=2x\) without the subtraction. However, the mean would have both operations applied, meaning the mean of \(y\) would now be the mean of \(x\) but timesed by 2 and subtracted 5.