what is mean median and mode

Mean, median, and mode are three different ways to talk about the “average” or central value of a set of numbers. They’re called measures of central tendency.

Mean (the usual “average”)

• The mean is what most people call the average.

• How to find it:
  1. Add up all the numbers.
  2. Divide by how many numbers there are.

Example:
Numbers: 4, 7, 9, 10
Sum = 4 + 7 + 9 + 10 = 30
Mean = 30 ÷ 4 = 7.5

• The mean uses every value, so one very large or very small number (an outlier) can pull it up or down a lot.

Median (the middle value)

• The median is the middle number when the data is put in order from smallest to largest.

• Steps:
  1. Sort the numbers.
  2. If there are an odd number of values, the median is the single middle one.
  3. If there are an even number of values, take the average of the two middle values.

Example (odd count):
Numbers: 2, 5, 7
Already in order, middle number is 5 → median = 5.

Example (even count):
Numbers: 1, 3, 4, 100
Middle two numbers are 3 and 4 → median = (3 + 4) ÷ 2 = 3.5.

• The median is not much affected by extreme values, so it’s useful when the data is skewed (like incomes where a few people are very rich).

Mode (the most frequent)

• The mode is the value that appears most often in the data.

• There can be:
  • No mode (if all values occur with the same frequency),
  • One mode (unimodal),
  • Or more than one mode (bimodal, multimodal).

Example:
Numbers: 2, 4, 4, 5, 5, 5, 9
5 appears three times, more than any other value → mode = 5.

• Mode works even for non‑number categories, like “most common T‑shirt size” (S, M, L, XL).

Simple comparison

[5][1] [5][1] [3][5] [5][1][3] [1][5] [3][5] [5][1][3] [1][3] [3]

Measure	What it is	How you calculate it	Sensitive to outliers?
Mean	Arithmetic average of all values.	Sum of values ÷ number of values.	Yes, strongly affected.
Median	Middle value when data is ordered.	Sort data, pick middle; if even count, average the two middle values.	No, mostly stable.
Mode	Most frequently occurring value.	Find the value(s) that appear most often.	No, usually not affected.

When to use which?

• Use the mean when:
  • You want a general average and there are no extreme outliers (e.g., average test score in a class with normal scores).

• Use the median when:
  • The data is skewed or has very large/small outliers (e.g., incomes, house prices).

• Use the mode when:
  • You care about the most common category or value (e.g., most sold shoe size).

Quick story to remember them

Imagine five friends compare how much money they have in their wallets: 5, 5, 10, 15, and 200.

• The mean will be pulled up by the friend with 200, so it will look like everyone is richer than they really feel.

• The median (the middle value when ordered) will be 10, which feels more like what “typical” people in the group have.

• The mode will be 5, showing that “5” is the amount most people actually have.

Bottom note: Information gathered from public forums or data available on the internet and portrayed here.