- Mean, Median, and Mode
- Home
- Mode of a Data Set
- Finding the Mode and Range of a Data Set
- Finding the Mode and Range from a Line Plot
- Mean of a Data Set
- Understanding the Mean Graphically: Two bars
- Understanding the Mean Graphically: Four or more bars
- Finding the Mean of a Symmetric Distribution
- Computations Involving the Mean, Sample Size, and Sum of a Data Set
- Finding the Value for a New Score that will yield a Given Mean
- Mean and Median of a Data Set
- How Changing a Value Affects the Mean and Median
- Finding Outliers in a Data Set
- Choosing the Best Measure to Describe Data

- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who

# Understanding the Mean Graphically: Four or more bars

In this lesson we understand the mean of a dataset using graphical method. Suppose we are given a bar graph showing four bars of data. Here we are required to find the mean of given data graphically.

## Rules to find the mean graphically

In the bar graph we find the heights of the four bars.

The average or mean of these heights is found.

We then draw a fifth bar with the average height found in second step.

The height of this fifth bar gives the mean or average of given data set graphically.

The four bars in a bar graph have heights 14, 16, 18, and 22. What height a new bar should have so that it is the mean height of the four bars?

### Solution

**Step 1:**

Heights of given bars 14, 16, 18 and 22

**Step 2:**

Mean height = $\frac{(14 + 16 + 18 + 22)}{4} = \frac{70}{4}$ = 17.5

So height of new bar = 17.5.

The four bars in a bar graph have heights 15, 16, 17 and 20. What height a new bar should have so that it is the mean height of the four bars?

### Solution

**Step 1:**

Heights of given bars 15, 16, 17 and 20

**Step 2:**

Mean height = $\frac{(15 + 16 + 17 + 20)}{4} = \frac{68}{4}$ = 17

So height of new bar = 17