Percentiles and Quartiles

Intuition of Percentiles and Quartiles

Previously, variance and standard deviation, which have already been explained, are units that show how scattered a dataset is. This time, percentiles and quartiles are more about "Where is this data positioned????".

If the mean answers:

"What is the average value?"

If variance answers:

"How spread out is the data?"

Well, in Percentiles and Quartiles, what is answered is:

"Where do I stand compared to others?"

What is a Percentile

To explain this in the easiest way to understand, imagine this scheme

Percentile divides data into 100 equal parts.

P25 means the 25th percentile, there are 25% of values below you and 75% of people have a higher value than you!!!

What is a Quartile

If percentiles divide data into 100, quartiles divide it into only 4 parts

As simple as the quote above is the understanding

Basic formulas for Percentiles and Quartiles

Percentile

Quartile

FUN FACT

Q2 is P50 or the middle value (in other words Q2 is the median)

When to Use Quartiles and When to Use Percentiles

Okay, so...

It has already been explained that Q1, Q2, and Q3 are the same as P25, P50, and P75.

So if you need the top 25%, 50%, or 75% value, just use quartiles. Conversely, if you want to find something like the top 1% of students or the top 1% of universities, use percentiles.

"Quartiles are used to divide data. Percentiles are used to determine ranking."