# Median vs. Tertile: What's the Difference?

Edited by Aimie Carlson || By Janet White || Updated on December 11, 2023
Median is the middle value in a data set, while tertile divides data into three equal parts.

## Key Differences

The median is the middle value in an ordered set of data, splitting it into two equal halves. In contrast, tertiles segment the data into three equal parts, each containing a third of the data.
Median represents the 50th percentile, directly indicating the central tendency of a data set. Tertiles, however, are more about distribution, dividing the data into lower, middle, and upper thirds.
The median is used when seeking a robust measure of central tendency, less influenced by outliers. Tertiles are employed for a more detailed understanding of data distribution, particularly in smaller data sets.
The median provides a quick snapshot of the data's center, while tertiles offer a broader view, highlighting potential skewness or asymmetry in the distribution.
The median is common in reporting incomes or property values to avoid skewing by extreme values. Tertiles are often used in educational assessments to categorize student performance into distinct groups.

## Comparison Chart

### Definition

Middle value of a data set.
Divides data into three equal parts.

### Purpose

Measures central tendency.
Assesses data distribution.

### Influence of Outliers

Less influenced by outliers.
More sensitive to distribution.

### Data Division

Splits data into two halves.
Splits data into three sections.

### Common Usage

Used in income and property.
Used in educational assessments.

## Median and Tertile Definitions

#### Median

The central or middle value in a data set.
The median age of the group was 30.

#### Tertile

One of the three equal parts of a data set.
His score was in the upper tertile of the class.

#### Median

A measure of central tendency in statistics.
The median is less affected by outliers than the average.

#### Tertile

A method of dividing a range of values into thirds.
The tertile analysis helped in categorizing the regions.

#### Median

A line or point dividing a figure into two symmetrical parts.
The median of a triangle bisects the opposite side.

#### Tertile

Each of the two points that divide an ordered distribution into three equal parts.
The first tertile marks the one-third point of the data.

#### Median

A value separating the higher half from the lower half.
The median income divides the population into equal halves.

#### Tertile

A statistical measure for data segmentation.
We used tertiles to understand customer spending habits.

#### Median

The midpoint in an ordered set of values.
In the set of numbers 3, 5, 7, the median is 5.

#### Tertile

A division in a distribution, particularly in a population study.
Age groups were divided by tertiles for the survey.

#### Median

Relating to, located in, or extending toward the middle.

#### Tertile

(statistics) Either of the two points that divide an ordered distribution into three parts, each containing a third of the population.

#### Median

(Anatomy) Of, relating to, or situated in or near the plane that divides a bilaterally symmetrical animal into right and left halves; mesial.

#### Tertile

(statistics) Any one of the three groups so divided.
The first tertile results include January through April's revenues.

## FAQs

#### What are tertiles?

Tertiles divide a data set into three equal parts.

#### What is a median?

The median is the middle value in an ordered set of numbers.

#### How is the median calculated?

By arranging data in order and picking the middle value.

#### Can the median be the same as a tertile point?

Yes, in some data sets, the median can be a tertile point.

#### How are tertiles determined?

By finding two values that split the data into three equal groups.

#### What's the difference between quartiles and tertiles?

Quartiles divide data into four parts, while tertiles into three.

#### What do tertiles indicate in a data set?

They show how the data is spread across three equal segments.

#### Why use the median instead of the average?

The median is less affected by extreme values or outliers.

#### How do tertiles help in understanding data distribution?

They provide a more detailed view of how data is spread.

#### Can the median be used for skewed data?

Yes, it's particularly useful for skewed distributions.

#### Are tertiles used in all types of data analysis?

They are more common in specific contexts, like educational performance.

#### Is median used in everyday life?

Yes, like median household income.

#### Is the median always a number in the data set?

Not always; it can be an average of two middle numbers in an even-sized set.

#### Is the median affected by the data set size?

No, it's independent of the size of the data set.

#### Can median be used for categorical data?

No, it's typically used for numerical data.

#### Do tertiles have standard values?

No, they change based on the data set.

#### Are tertiles useful in market segmentation?

Yes, for dividing populations into three categories.

#### What happens to the median in a bimodal distribution?

It still represents the middle point.

#### Can tertiles be used for time series data?

Yes, especially to observe trends over periods.

#### Is the median always a clear indicator of data tendency?

Mostly, but it's one of many statistical tools.