Mean

Let's start with an example. Say the Organizers of Wimbledon decided to take the visiting tennis players around London on a bus. Some 10 players boarded the bus. Someone was curious to know the average weight of these players. How do you go about calculating that?

Mean works on simple math. Take the individual weights of all the players, sum them up, and then divide the sum by the number of players. Let's do this.

Here is the list of players and their weight in kg.

Novak Djokovic - 77

Daniil Medvedev - 83

Rafael Nadal - 85

Dominic Thiem - 82

Stefanos Tsitsipas - 85

Alexander Zverev - 86

Andrey Rublev - 85

Roger Federer - 85

Diego Sebastian Schwartzman - 65

Matteo Berrettini - 95

The Mean of these values is 82.8. As we discussed, you simply add all the values (sums up to 828) and then divide the sum by the number of values (10 in this case).

Is Mean a good description of the data at hand?

Let's find out in the next section.