The mean, the median and the mode

Mean, median and mode are numbers that represent a whole set of data or information. Mean, median and mode are together called the measures of central tendency.

The mean is often called the average. To find the mean you take a set of data and calculate the sum of the data, after that you divide the sum by the number of pieces in the set.


Example

Find the mean of the following data set:

56, 35, 45, 67, 12, 24, 48, 55, 58, 30

$$\frac{56+35+ 45+ 67+12+24+ 48+ 55+ 58+ 30}{10}=$$

$$=\frac{430}{10}=43$$

$$The\: mean=43$$

The median is the number in an ordered set of data that is in the middle.

If we have a set of data with an odd number of data points then the median is the data point in the middle.

$$1,2,3,{\color{red} 4},5,6,7$$

If we have a set of data with an even number of data points, then the median is the mean of the two data points in the middle

$$1,2,3,{\color{red} 4,5},6,7,8$$

$$\frac{4+5}{2}=\frac{9}{2}={\color{red} {4.5}}$$

The mode is the most common number in the set of data.


Example

$$2,5,6,2,2,2,5,6,2$$

$$The\, mode=2$$


Video lesson

Find mean, median and mode