I'm a chain store and have many stores across the country that all sell a particular shampoo product P.
I have made a plot as shown in the image below. For example, 30 stores each sold 1 of P in the past two weeks. The sum of the areas of the bars is the total number of P sold across all stores in the past two weeks.
What should be the theoretical shape of this plot? You may assume anything that gives a clean answer to this.