 # Mean, Median & Modal Value

Mean, median and modal are measures that describe the centre or position of the data.

## Arithmetic mean value

The arithmetic mean is the average value of all values or measurements. All individual values are taken into account when calculating the mean value. The mean value is very strongly influenced by outliers.

## Median

The median is the middle value of a series of numbers arranged in ascending or descending order. In a data set with an even number of values, the median is the average of the two middle values. This means that not all data are included. The median is robust to extreme data values and is therefore often more suitable than the mean for making a statement about skewed data distributions.

## Comparison of mean and median

If you think of 9 balls of equal weight on a rod that is negligible in weight, then the mean value represents the centre of gravity of the system. The median is the middle ball.

It is advisable to always consider the mean and median together.

## Modal value or mode

The mode or modal value is the value that occurs most frequently in an observed set of data. The modal value is also used for attributive data. For these attribute values, as with variable data, the modal value is the value that occurs most frequently.

## Example

In a medium-sized company, the number of new customers per month was documented over a period of time to monitor the effectiveness of investments in sales.

In the last month listed, the number of new customers increased drastically. This is related to a company merger in the same period.

The following values were documented: For the data listed, the result is:

a mean value of 11.80

a median of 6

a modal value of 3

with a number N for the modal value of 4 