Thanks to this short post, you get a useful piece of advice related to measures of location, recall an important formula and are offered a practical tip.
Before computing any measure of location (like percentile, median, etc.), sort observations in an ascending or a descending order.
Formula for the location of a percentile
- \(y\) – percentile,
- \(L_y\) – location of the percentile,
- \(n\) – number of observations.
Measures of location: practical tip
If the location of the percentile is not an integer, we need to apply linear interpolation to compute this percentile. Have a look at the example.
There is a set of numbers given in the ascending order: 2, 12, 23, 34, 45, 55, 65, 83, 87 and 89. Determine the value of the 20th percentile.