Percentile Rank

Problem

Return the mid-rank percentile of value within scores: 100 * (count(scores < value) + 0.5 * count(scores == value)) / n. Half of the tied scores count as below, so the maximum of a distribution with ties does not automatically score 100. Return 0.0 for empty input.

Hint

The mid-rank convention gives tied scores half credit.

Test cases

case 1

in: [[1,2,3,4],2.5]

expected: 50

case 2

in: [[1,2,2,3],2]

expected: 50

case 3

in: [[1,2,3,4],4]

expected: 87.5

case 4

in: [[5,5,5],5]

expected: 50

case 5

in: [[1,2,3,4],0]

expected: 0

Starter codePython

def percentile_rank(scores, value):
    # Your code here
    pass

5 test cases · run your code against them in the editor