Chapter 7, Problem 1FCCE

What is a bar chart? A pie chart? A histogram? A box plot?

To determine

The meaning of a bar chart, a pie chart, a histogram and a box plot.

Explanation of Solution

Bar chart:

Bar chart is a pictorial display of provided data by rectangular bars. Bar charts can be shown vertically or horizontally.

For example, the percentage of student to give highest degree planned to pursue, is provided in a table.

Highest degree planned	Percentage
Bachelor’s	21.1
Master’s	42.1
Doctorate	19.0
Medical	11.2
Law	4.2
Others	2.4
Total	100.0

The representation of the data in a bar chart is provided below.

Pie chart:

Pie chart consists of a circle subdivided into sectors in which each sector corresponds to a category. The area of each sector is proportional to the percentage of items in that category.

For example, the data is shown in a tabular form.

Highest degree planned	Percentage	$360°\times \text{percent}$
Bachelor’s	21.1	$76.0°$
Master’s	42.1	$151.6°$
Doctorate	19.0	$68.4°$
Medical	11.2	$40.3°$
Law	4.2	$15.1°$
Others	2.4	$8.6°$

The representation of data in a pie chart is provided below.

Histograms:

A histogram represents a graphical or visual interpretation of data. It is similar to the bar graph except, it has no gaps between the bars. The data are represented between x-axis and y-axis. The x-axis represents a scale of values and y-axis represents a value which corresponds to a value of $x$.

For example- the quiz score of 25 students of a class are,

$8,7,6,10,5,10,7,1,8,0,10,5,9,3,8,6,10,4,9,10,7,0,9,5,8$.

The quiz score data of students are shown in a tabular form.

Scores	0	1	2	3	4	5	6	7	8	9	10
Number of student	2	1	0	1	1	3	2	3	4	3	5

The representation of the quiz score data in a histogram is provided below.

Box plot:

A box plot shows a graphical representation of collection of data through quartiles. Quartiles are the medians of the sets of data to the left and right to the median.

The median of the numbers less than the median is called the first Quartile $\left({\text{Q}}_{\text{1}}\right)$ and the median of the numbers greater than the median is called third quartile $\left({\text{Q}}_{\text{3}}\right)$. The general box plot is shown below.

Here, the ${\text{Q}}_{\text{1}}$ and ${\text{Q}}_{\text{3}}$ shows the ends of the box and ${\text{Q}}_{\text{2}}$ shows the median of the box.