I am interested in learning descriptive statistics. But I am completely baffled, that there seem to be no mathematically rigorous books on this subject, as far as I know at least. The Wikipedia page states, that descriptive statistics is not based on probability theory. If that is the case, then on what is it based on?
It could be that this field is simply not an area of mathematics. However, I believe this idea to be rather absurd, since it is clearly using some level of regular mathematical reasoning. I am not in any way saying that when teaching a subject, mainly appealing to intuition is bad, but rather that developing mathematics "in thin air" is fairly unsatisfactory.
Given all this how do I, a rather mathematically-inclined person, go about learning descriptive statistics?
Some general statements about the nature of said subject with respect to what I talked about may be helpful as well as links to any potentially useful material.
Descriptive statistics is a part of mathematics, but it is generally thought at high school. It is not useful to mathematicians. This also gives the reasons why there is no book:
However, you need descriptive statistics to give your information as clearly as possible. For example, when you want to show how many per cent of the tax money is spent at each category, a pie chart is useful. When you want to compare the amount of tax paid per country, a bar chart may be more useful.
The mathematical part of descriptive statistics is learning about how to compute or create all those diagrams or central tendencies. This is not hard: The formulas are actually easy, and creating diagrams is more learning how to use software than learning maths. The non-mathematical part is deciding between all those diagrams and statistics. This is actually the harder part for a mathematician.