Question

Stem Plot of Body Temperatures Construct a stem plot of the body temperatures listed in Exercise 1. Are there any outliers?

Short answer

The following stem plot is constructed.

As there are no values that are far off from the other observations, it can be said that there are no outliers in the data.

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 stem plot

A stem plot is a graph that displays all the values in the form of stems and leaves.

When data has values with one decimal place, the stems are the whole number part and are written on the left side, while the leaves are the decimal part and are written on the right side.

The leaves and stems are separated by a vertical line and are arranged in rows.

Sketch the stem plot

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

• Arrange the temperatures in the ascending order.
• Consider the whole number part of the observations as the stems, and write all the unique values in successive rows.
• Consider the decimal parts of the observations as leaves.
• Arrange the stems on the left side of a vertical line and the leaves on the right side by writing the decimal part of each observation on the right side of each stem.
• Write the key of the plot.

The following stem plot is constructed.

Key: 99.|1 represents a body temperature equal to 99.1 degrees Fahrenheit.

Identify the outliers

An outlier in a dataset is an extreme value.

In the case of a stem plot, if a row is far off from the other rows in the stem plot, the value corresponding to that row is considered an outlier(extreme value).

As no value lies at a large distance from the rest of the values, there are no outliers in the dataset.