Help on selecting values in list making up the top total percentage

[pc_qci]

Can someone please help me to find a function or formula that I can show, e.g. the top 80% values of the total?

For example

Value list: 1,7,4,2,5,6,3,8

Total: 36

80%: 28.8

Top 80% values should be make up by: 8,7,6,5,4

(Including 4 and the sum of these 5 values is 30 and it is 83.33% of the total)

I tried percentile and percentrank which only based on the list of value or number, not the total.

[#2]

@pc_qci 

Hi 

The attache gives a possible solution but it is not very elegant.

I am not sure what you are trying to do in your application - this may help!

all the best.

Peter