# 7 - Statistics

## Mean

You know how to calculate the mean of 3 marks. But do you know how to calculate the mean of 3 marks with coefficients? Elsa got 12, with coefficient 2, 18 with coefficient 1, and 14 with coefficient 2. What is her average mark? It is quite simple, you must have :

## Median

The median of a series of numbers, it is the number which divides the series into two equal parts when the series is set in an increasing order. For example, the median of numbers 2, 7, 3, 4, and 6, is 4 because there are as many numbers greater than 4 as numbers smaller than 4. It is as simple as that. When you have an even number of values (1, 2, 7, 9, 10, 13, 14, 15), you take the value between the two middle values. Here it will be 9,5.

## Range

It is a very simple notion. The range of a series of statistics is equal to the subtraction between the highest and the smallest value. For the series 1, 2, 7, 9, 10, 13, 14, 15, the range is equal to 14.

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Statistics

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