Define Mean and Median,and also the Difference..

**The mean is the average of the numbers:** A calculated "central" value of a set of numbers.

To calculate the mean, ust add up all the numbers, then divide by how many numbers there are.

Example: what is the mean of 2, 7 and 9?

Mean=(2 + 7 + 9) ÷ 3 = 18 ÷ 3 = 6

The** Median** of a data is the value of the middle observation, when the data is arranged in ascending or descending order. The median divides the data into two equal halves.

Suppose the observations are:

31, 9, 8, 20, 15, 8, 3, 30, 31, 23, 13, 13, 28, 26, 19, 27, 13, 12, 25

These observations can be arranged in ascending order as:

3, 8, 8, 9, 12, 13, 13, 13, 15,

**19**, 20, 23, 25, 26, 27, 28, 30, 31, 31Here the middle most term is 19. There are 9 terms before 19 and 9 terms after 19. Thus,

**the median of the given observations is 19.**

From the above definitions, you can easily differentiate these two.

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