Mean Median Mode

Definition

Actually mean, median, and mode are basically super easy! In fact, since middle school (Sekolah Menengah Pertama) you’ve probably studied them already

Mean

Mean is another word for average

the formula is simple:

The point is, it’s simple: just add all the data and divide by the number of data points

Median

Mean is another word for the middle value of a sorted data set

If you’re confused by the formula above, simply put: if the data count is odd (1,3,5,7), then the middle value is the number of data points (4) plus 1, then divided by 2

if the number of data points is even (2,4,6,8), then the median is the average of the two middle values, namely data point and data point

The point is, if the count is odd, there’s only 1 middle value, but if it’s even, there are 2 middle values, so just add them and divide by 2 (like the mean of the median)

Mode

Mode is another word for the most frequently occurring value

Mathematically, the formula can actually be written like this:

from the data side, just count each element

Differences in Usage

The concepts of mean, median, and mode are super easy to understand, but for a beginner analyst, it’s often confusing when to use them in presenting data.

Actually, there is no rule of thumb for when to use them in data presentation; use the value that is more representative. Simply follow this guideline:

Use the mode to represent favorite data, use the median when there are many outliers, use the mean for normal distributions

If you’re still confused, look at the example below

Example analysis using mean, median, mode

Suppose a tech division consists of:

3 software engineers with salaries of 8 million
2 software engineers with salaries of 16 million
1 CTO with a salary of 100 million
1 product manager with a salary of 24 million

Then a question comes from a new employee candidate, what are the salaries like at Data Skill Foundry?