Decile for Undgrouped Data
Deciles
The deciles are the nine score points which divide a distribution into ten equal parts. They are deciles and are denoted as D1, D2, D3........D9. They are computed in the same way that the quartiles are calculated.
Example 1
Find the 3rd decile of D3 of the following test scores of a random sample of ten students:
35, 42, 40. 28, 15, 23, 33, 20, 18, and 28.
Solution
First, arrange the scores in ascendig order,
15 18 20 23 28 28 33 35 40 42
Steps to find decile value on a data with n elements:
To find its D3 position, use the formula 3/10(n +1) and round off to the nearest integer.
D3 is the 3rd element.
Therefore, D3 = 20