Find Mode by Histogram 

In this tutorial, we will learn, how to find mode of a given observation with the help of a histogram. 
First we know about mode. What is mode?

Definition: 

The mode of a data set is the value, occurring most frequently in set of observations. In other words, a data set having highest frequency of observations is its mode.

Example: Find the mode of the following set of data.
1,  3,  9,  5,  9,  7,  7,  9,  5,  7,  7

Put the numbers in numerical order(lowest to highest)

1,  3,  5,  5,  7,  7,  7,  7,  9,  9,  9, 

In above example 7 is the highest frequency, so mode is 7.

A set of numbers having one or single mode is called “Unimodal”.

Example: Find the mode of the following set of data.1,  4,  1,  10,  8,  10,  5,  10,  5,  8,  3,  8

Put the numbers in numerical order(lowest to highest)

1,  1,  3,  4,  5,  5,   8,  8,  8,  10,  10,  10

In above example 8 and 10 has the highest frequency, so there is two modes 8 and 10.

A set of numbers having two modes is called” Bimodal”.

Example: Find the mode of the following set of data.1,  2,  4,  1,  5,  9,  9,  7,  2,  10,  2,  5,  7,  5,  9, 5, 9, 7,  7

Put the numbers in numerical order(lowest to highest)

1,  1,  2,  2,  2,  4,  5,  5,  5,  5,  7,  7,  7,  7,  9,  9, 9,  9,  10.

In above example 5, 7 and 9 has the highest frequency, so there are three modes 5, 7 and 9.

A set of numbers with three modes is called “Trimodal”. 

Example: Find the mode of the following set of data.1,  2,  4,  1,  5,  4,  9,  4,  9,  4,  7,  2, 10,  2,   5,  7,  5,  9,  5,  9,  7,  7.

Put the numbers in numerical order(lowest to highest)

1,  1,  2,  2,  2,  4,  4,  4,  4,  5,  5,  5,  5,  7,  7,  7,  7,  9,  9,  9,  9,  10.

In above example 4, 5, 7  and 9 has the highest frequency, so there are four modes 4, 5, 7 and 9.

A set of numbers with four or more then four modes is “Multimodal”.