Chapter 1.2, Problem 60E

a.

To determine

To construct: The stem plot for the provided data.

Explanation of Solution

Given:

The data set is:

7.5
8.2
8.9
9.3
7.1
8.3
8.7
9.5
8.2
9.1
9
9
9.7
9.2
8.9
8.1
9
7.8
8
7.8
7
7.5
13.5
8.3
6.8
10.6
8.3
7.6
7.7
8.1

Graph:

The stem plot could be constructed as:

  

b.

To determine

To explain: The feature that is shown by the plot constructed in above part.

Explanation of Solution

The above plot shows that the data has not been taken from the population that is normally distributed because of the presence of the outlier in the data set. Here, value 13.5 is an outlier.

c.

To determine

To find: The proportion of varieties that contain more than 9 grams of protein per 100 grams.

Answer to Problem 60E

The proportion is 23.33

Explanation of Solution

Number of varieties = 30

Number of varieties that contain more than 9 grams of protein = 7

The proportion of varieties that contain more than 9 grams of protein can be calculated as:

  $\begin{array}{c}\text{Proportion of varieties = }\frac{\text{Number of varieties}}{\text{Total varieties}}\times 100\\ =\frac{7}{30}\times 100\\ =23.33\end{array}$

The required proportion is 23.33