Percentiles for ungrouped data

Percentiles are the values of arranged data which divide whole data into hundred equal parts. They are 9 in numbers namely $P_1,P_2, \cdots, P_{99}$. Here $P_1$ is first percentile, $P_2$ is second percentile, $P_3$ is third percentile and so on.

Formula

The formula for $i^{th}$ percentile is

$P_i =$ Value of $\bigg(\dfrac{i(N+1)}{100}\bigg)^{th}$ observation, $i=1,2,3,\cdots,99$

where $N$ is the total number of observations.