Solution Manual for Business Analytics, 4th Edition, Jeffrey D. Camm, James J. Cochran, Michael J. Fry, Jeffrey W. Ohlmann

Solution Manual for Business Analytics 4th Edition

2.   A scatter diagram showing the relationship between the number of pages viewed and the time spent on the web site follows:

The sample correlation coefficient between these two variables is .596. The scatter diagram and the sample correlation coefficient indicate a postive relationship between the number of pages viewed and the time spent on the web site. 

Summary: The analysis indicates that online shoppers who spend more time on the company’s web site and/or view more web site pages spend more money during their visit to the web site. If Heavenly Chocolates can develop an attractive web site such that online shoppers are willing to spend more time on the web site and/or view more pages, there is a good possiblity that the company will experience greater sales. And, consideration should also be given to developing marketing strategies based upon possible differences in sales associated with the day of the week as well as differences in sales associated with the type of browser used by the customer.         

Case Problem 2: African Elephant Populations

This case provides the student with the opportunity to use the geometric mean in conjunction with a graph (such as the boxplot) to analyze changes over time in the populations of elephants in several African nations.

1.      Let’s calculate the proportional change for each country over the 10-year period, 1979–1989. We’ll begin by considering the Central African Republic. We have:

 19,000 = 63,000 x x1 2 x10 , so x x1 2 x10 = 0.301587 and xg  n x x1 2 x10 10 0.301587  0.887036

 So the mean annual change in the elephant population for the Central African Republic during this period is (0.887036 – 1)100% = –11.3%. From 1979 to 1989, the elephant population in the Central African Republic declined at an annual rate of 11.3%.

Repeating these calculations for each nation yields the values in the following table.

Country                  x x1 2 x10            xg      Mean Annual Change

 The elephant populations in several nations (Central African Republic, Chad, Democratic Republic of the Congo, Kenya, Mozambique, Somalia, Tanzania, and Zambia) declined at an annual rate of 10% or more from 1979 to 1989. During the same period a few nations (Botswana, Congo, and Gabon) experienced growth in their elephant populations.

2.         Now let’s calculate the proportional change for each country over the 18-year period, 1989–2007. We’ll again begin by considering the Central African Republic. We have:

3,334 = 19,000 x x1 2 x18 , so x x1 2 x18 = 0.175474 and xg  n x x1 2 x18 18 0.175474  0.907845

         So the mean annual change in the elephant population for the Central African Republic during this period is (0.907845 – 1)100% = –9.2155%. From 1979 to 1989, the elephant population in the Central African Republic declined at an annual rate of 9.2%.

Repeating these calculations for each nation yields the values in the following table.

Country                 x x1 2 x18            xg       Mean Annual Change

 Only one country (Somalia) continues to experience average annual declines of 10% or more in its elephant population from 1989 to 2007, while most other nations had relatively small mean annual changes in their elephant populations.

3.         Now let’s calculate the proportional change for each country over the five-year period, 2007–2012. We’ll again begin by considering the Central African Republic. We have:

So the mean annual change in the elephant population for the Central African Republic during this period is (0.927223 – 1)100 = –7.2777%. From 2007 to 2012, the elephant population in the Central African Republic declined at an annual rate of 7.3%.

Repeating these calculations for each nation yields the values in the following table.

 Two countries (Chad and Democratic Republic of the Congo) experienced average annual declines in their elephant populations of 10% or more from 2007 to 2012, while most other nations had relatively small mean annual changes in their elephant populations.

4.         Now we compare the results of our three analyses and draw conclusions.                 Mean Annual