Mean, Median, Mode: Differences and when to use them?

Mean, median, and mode are the three kinds of “averages”. While everybody is aware of the Mean, which is also known as the Arithmetic Mean or just the ‘average’ that everybody is aware of, there are a few other type of averages as well.

And even if you know what is a Mean, Median and Mode, do you know where and how are these used?

Students learn about these things in school from the books, but they never tell you why you should care about it how these can be useful.

So let’s understand how and when to use them.

• Mean: Average of all the numbers, where you add up all the numbers and then divide by the number of numbers.
• Median: It is “middle” value in a list of numbers.
• Mode: The most occurring numbering in a list of numbers.

Knowing which method to use depends on the type of data you are working with, and the purpose why you want to use either mean, median or mode.

When to Use Mean?

Mean is used when the data is symmetrical meaning there are no extreme highs or lows in the numbers. A number to the extreme will skew the data so that the mean becomes much higher or lower.

Mean also gives equal weight to every value so it is useful in calculating grade averages, sports statistics and average speeds.

The following data showing ages of kids:

10, 12, 12, 25, 11 , 17, 15, 2

This set of data would not be a very good set for using mean because it is asymmetrical which means there are numbers that are way higher or way lower than most of the numbers. So 10 and 15 are generally near each other but 2 is way lower than those numbers and 25 is so much higher.

When to Use Median?

While this set would not be good for calculating mean, the Median is commonly used with asymmetrical data. Median gives less weight to the values at the extremes.

Median is most useful when comparing things like prices where a consumer may not want to buy the cheapest or the most expensive but wants to find a price right in the middle.

For example, a buyer looking to buy a house in a neighborhood might look to find the median prices of the houses sold in that area because he wants to know the price for a house that is not too expensive because it might be overpriced for the neighborhood but not too inexpensive because it might be in bad condition.

When to Use Mode?

Mode is useful to find the most common or most popular results of surveys elections and lists of things.

For example, you might be interested in knowing which school has won the tennis championship most often in the last 10 years. You would be listing out the Championships won by each school in the last 10 years. The mode of that number will give you the school which won the championship the most in the last 10 years.