Chapter 1.2, Problem 45E

a.

To determine

To construct: The dot plot for the provided data.

Explanation of Solution

Given:

The data set is:

9
6
8
7
8
8
6
6.5
7
7
9
4
3
4
5
6
11
6
3
7
6
10
7
8
4.5
9
7
7

Graph:

The dot plot could be constructed as:

  

b.

To determine

To find: The proportion of students that took recommend amount of sleep.

Answer to Problem 45E

The proportion is 17.857.

Explanation of Solution

The recommended amount of sleep is at least 9 hours.

The number of students that slept at least 9 hours are 5.

Number of students = 28.

The proportion of students that took recommend amount of sleep can be calculated as:

  $\begin{array}{c}\text{Proportion of students = }\frac{\text{Number of students that slept at least 9 hours}}{\text{Total students}}\times 100\\ =\frac{5}{28}\times 100\\ =17.857\end{array}$

The required proportion is 17.857.