Deciles for ungrouped data
Deciles are the values of arranged data which divide whole data into ten equal parts. They are 9 in numbers namely $D_1,D_2, \cdots, D_9$. Here $D_1$ is first decile, $D_2$ is second decile, $D_3$ is third decile and so on.
Formula
The formula for $i^{th}$ decile is
$D_i =$ Value of $\bigg(\dfrac{i(N+1)}{10}\bigg)^{th}$ observation, $i=1,2,3,\cdots, 7$
where $N$ is the total number of observations.
