Explain what a percintel is? How is it calculated? What is its calculation formula, if it exists.
For example, a set of such data is given:
How to calculate the 99th percentile? 90th?
Answer 1, authority 100%
To get the percentile p , the data must be split so that p% of the data on the left, 100-p% of the data on the right, and the delimiter (right-most of the left) is greater than (or equal to ) of all left, and less (or equal) of all right.
In particular, this can be achieved by sorting the data and getting the element with the index
p * N / 100(sorting is somewhat redundant for this action, but if the data is already sorted, the rest is simple).
For example, the median (percentile 50) is an element that is more than half of the elements and less than the other half. For the given set, the median is 5.
A quartile is more than a quarter of the elements. The second quartile coincides with the median, and in a broader sense, this can be called a part of the dataset from the first quartile to the median, etc.
The set given in the question is too short, so the specified percentiles will be on the largest element.
Answer 2, authority 50%
Percentile is an indicator used in statistics that shows the value below which a certain percentage falls
observations in the observation group
If not enough, here’s a link to wikipedia everything is there detailed