Chapter 4, Problem 12E

(a)

To determine

To Explain: the mean and median to be larger expected.

Explanation of Solution

Given:

  

Average of the data list is known as the mean, whereas the middle number of a data list dividing the higher half from the lower half is called the median. it requires to find whether the mean or the median is larger. The mean is greater than the median because the histogram is skewed to the right.

(b)

To determine

To Explain: the few sentences describing this distribution.

Explanation of Solution

Given:

  

It is require explaining the histogram in reference to its shape, centre and spread and any unusual feature. The distribution is positively skewed or skewed to the right, it represent that the data is not evenly distributed and it represent a longer tail to the right. The spread of the data is between 1 to 21 e-mails. There is an outlier because there is nothing between 9 and 20 e-mails.

(c)

To determine

To Explain: the summary statistics would select to summarize the centre and spread in these data.

Explanation of Solution

Given:

  

By seeing the histogram, it is observed that the distribution is the histogram is skewed to the right or not symmetric so the median instead of the mean and inter quartile range to summarize the spread of the data. Difference between the upper quartile is the inter quartile range, representing 75% of the data and 25% of the data is showing the lower quartile data.