IQR of a frequency
 

Hello,

This is my 1st time posting on this forum so please excuse any lack of information.

I am trying to write a template for finding descriptive stats for grouped data. i have 9 total stat formulas written and i cannot get this one or find it anywhere.

The stat i need is Interquartile range. i can easily do it for a normal set of data, but for a frequency data set i cannot get any known formula to work.

for instance this data:

0 10
1 15
2 27
3 18
4 38
5 57
6 22
7 5
8 2
9 3
10 0

what would the formula be?

Thank you in advance for any help

- Lonehunter

I guess to better explain what the IQR is; it is the third quartile minus the first quartile. so my question should be how do i find the different quartiles for a frequency distribution.