Question

Dot Plot of Body Temperatures constructs a dot plot of the body temperatures listed in Exercise 1. Which does a better job of illustrating the distribution of the data: the histogram from Exercise 2 or the dot plot?

Short answer

The following dot plot is constructed.

The histogram is a better graphical representation for the data on body temperatures as it utilizes a fewer number of classes/points and displays the data more compactly and effectively.

Step-by-step solution

Given information

Data are given on body temperatures of 20 subjects measured in degrees Fahrenheit.

Refer to Exercise 1 for the data.

97.1 97.2 97.5 97.6 97.6 97.8 98.0 98.0 98.2 98.2

98.2 98.3 98.4 98.6 98.6 98.7 98.7 98.9 99.1 99.4

Describe a dot plot

A dot plot is a graph that displays the frequencies of observations using a point along a reference number line marked horizontally.

The points are plotted corresponding to this horizontal axis.

If observations are recurring, the points are stacked over one another.

Sketch the dot plot

The following steps are adopted to sketch the dot plot for the given data.

• Mark the values from 97.0 to 99.5 on a horizontal scale with a gap of 0.5 units between each successive value.
• Mark the points above the corresponding value of the temperature. If observations get repeated, place a point above the previous point.
• Label the horizontal axis as ‘Body Temperature’.

The following dot plot is constructed.

State the differences between the dot plot and the histogram

Refer to Exercise 2 for the histogram of the data.

A dot plot consists of points for all the values in the data. This can sometimes make the plot messy and difficult to comprehend, especially if there are a large number of values.

A histogram summarizes all the values into a few class intervals. This makes the representation more concise and easy to understand.

Therefore, a histogram is better than a dot plot to depict the temperatures as it uses fewer values/classes and makes the graph easy to understand.