Chapter 1.7, Problem 13E

(a)

To determine

Find the sample mean.

Find the median.

Answer to Problem 13E

The sample mean is 124.3.

The median is 120.

Explanation of Solution

Calculation:

Step-by-step procedure to obtain the mean and median using MINITAB software:

• Choose Stat > Basic Statistics > Display Descriptive Statistics.
• In Variables enter the column hour.
• Choose option statistics, and select Mean, Median.
• Click OK.

Output obtained using MINITAB software is given below:

From the MINITAB output, the sample mean is 124.3, and the median is 120.

(b)

To determine

Identify the feature in this data set that is responsible for the substantial difference between the two.

Explanation of Solution

Step-by-step procedure to obtain the boxplot using MINITAB software:

• Choose Graph > Boxplot.
• Under One Y, choose Simple. Click OK.
• In Graph variables, enter the data of hour.
• Click OK.

Output obtained using MINITAB software is given below:

From the boxplot, it is clear that the observation 175 is an extreme value when compared to the remaining observations.