Question

Explain Deciles.

Answer 1

Just like quartiles, we have deciles. While quartiles sort the data into four quarters, deciles sort the data into ten equal parts the 10^th, 20^th, 30^th, 40^th, 50^th, 60^th, 70^th, 80^th, 90^th,100^th.

The higher the place in the decile ranking, the higher is the overall ranking. For example, a person receiving 99 percentiles in a test would be placed in a decile ranking of 10. However, a person receiving 5 percentiles in the same test would be placed in a decile ranking of 1.

The mathematical formula to calculate decile is:

Where n is the number of data in the population sample.

i is the i^th decile and can be represented as:

1^st Decile, D₁ = 1 * (n + 1)/ 10^th data 

2^nd Decile, D₂ = 2 * (n + 1)/ 10^th data