ABSTRACT
Statistics is a tool that helps researchers or analysts to summarize their data in a smaller amount of comprehensive numbers. For example, when a business analyst has information on the monetary value of last year’s purchases of all customers of the company, a straightforward way to deal with this information is to summarize the possibly thousands of data points with the mean value. Indeed, the mean value gives us some idea about last year’s sales, but it gives a rather incomplete picture of what really is going on. For example, is the mean value a good approximation for the typical customer, or is this value overrated because of a few outstanding customers? Do customers deviate strongly from this mean value or not? These questions can only be answered by calculating other summary statistics than the mean on our sample.
