Compute median / percentile of grouped data

[FVerg]

Hi everyone

I'm facing an issue in QlikSense, trying to compute some statistical indicators (Percentiles, Quartiles, StdDev, Median etc.) on a dataset which is already grouped by the source.

I mean that my dataset is something similar to the following, in which I have for each combination of Week and Customer Age the total number of purchases:

Week	Customer Age	# Purchases
1	18-20	2
1	21-23	5
1	24-26	15
1	27-30	5
1	31-33	7
1	34-36	6
2	18-20	3
2	21-23	5
2	24-26	5
2	27-30	10
2	31-33	7
2	34-36	6
3	18-20	5
3	21-23	10
3	24-26	10
3	27-30	5
3	31-33	6
3	34-36	8

II want to show the median of Customer Age, and due to the structure of the dataset I can't use fractile or median built-in functions, since they would come out with something different.

Let's suppose I want to calculate the median age of people for all the 3 weeks, so that I want to know what's the age of people who have done the 50% of my purchases.

To let you better understand the question, I show you the histogram:

In this case, the median I want to get is 24-26 years, since the 50% of the total population falls under that range.

I found a useful reference here, but I am having troubles in writing this formula in QlikSense

https://mba-lectures.com/statistics/descriptive-statistics/603/relationship-between-quartiles-decile...

Thanks a lot in advance.

[Wlad_Masi]

I can see you already have the chart created, you want that value in a KPI?