All the branches of XYZ school conducted an aptitude test for all the students in the age group 14 - 16. There were a total of n students. The marks of n students are stored in a list. Write a program using a user defined function that accepts a list of marks as an argument and calculates the ‘x^{th}’ percentile (where x is any number between 0 and 100).You are required to perform the following steps to be able to calculate the ‘x^{th}’ percentile.

**Note:** Percentile is a measure of relative performance i.e. It is calculated based on a candidate’s performance with respect to others. **For example:** If a candidate's score is in the 90^{th} percentile, that means she/he scored better than 90% of people who took the test.

**Steps to calculate the x**^{th} percentile:

I. Order all the values in the data set from smallest to largest using Selection Sort. In general any of the sorting methods can be used.

II. Calculate index by multiplying x percent by the total number of values, n.

**For example:** to find 90^{th} percentile for 120 students: 0.90*120 = 108

III. Ensure that the index is a whole number by using math.round()

IV. Display the value at the index obtained in Step 3.

The corresponding value in the list is the x^{th} percentile.