Create a Quintile Column (1,2,3,4,5) and assign the top 20% of rows to Q1, next 20% to Q2, ..

[Anonymous]

I am very new to excel and Power BI and have tried using the built in percentile.inc, exc functions with no success so far. 

This is my thought process:

I have a dataset with a 'Score' (%) column at hand. I sorted this column in descending order and then added another column 'Rank' to calculate the score's rank using the RANKX function. Now I want to create a 'Quintile' column which takes the top 20% of the highest scores and assigns the associated quintile row to 1, next 20% of scores to 2, ... bottom 20% of scores are assigned 5. Is there an easier way to assign these quintiles even when not in descending order, and if so can someone with knowledge on this provide an example of a function that would work for this? Thanks in advance. 

[amitchandak · Accepted solution]

@Anonymous , refer if these can help

https://blog.enterprisedna.co/implementing-80-20-logic-in-your-power-bi-analysis/
https://forum.enterprisedna.co/t/testing-the-pareto-principle-80-20-rule-in-power-bi-w-dax/459

[CloudHerder]

Why was this accepted as a solution when it doesn't answer the question?