CHAPTER TWO HOMEWORK

  1. Solve the following problems. Submit graphs and charts on the Blackboard after you create them in Excel. The other questions still need to be submitted in hard copy.

 

  1. A categorical variable has three categories with the following frequencies of occurrence:

 

Category                                                                 Frequency

                           A                        13
                           B                        28
                           C                          9

 

  1. Compute the percentage of values in each category.
  2. Construct a bar chart for percentage.
  3. Construct a pie chart for percentage.
  4. Construct a Pareto diagram.

 

  1. A survey of 705 workers asked how much they used the Internet at work. The results (USA Today Snapshots, March 21, 2006) were as follows:

 

Use of the Internet at Work                                              %

                 Too much                        5
                 More than I should                        4
                 Within limits                      60
                 Very little                        5
                 Do not use                      26

 

  1. Construct a bar chart, a pie chart, and a Pareto diagram.
  2. Which graphical method do you think is best to portray these data?
  3. Based on this survey, what conclusions can you reach about the use of the Internet at work?

 

  1. S. companies spent more than $250 billion in advertising in 2005 (K. Delaney, “Google Steps Further into World of Old Media,” The Wall Street Journal, January 18, 2006, pp. A1, A6). The spending was as follows:

 

Media                                                      Amount ($billions)                             Percentage (%)

Cinema                     0.4                       0.16
Direct mail                   44.5                     17.35
Internet                   10.0                       3.90
Magazines                   23.9                       9.32
Newspapers                   50.2                     19.57
Outdoor                     5.7                       2.22
Radio                   20.6                       8.03
TV                   55.4                     21.60
Other                   45.8                     17.86

 

  1. Construct a bar chart and a pie chart for percentage.
  2. Which graphical method do you think is best to portray these data?

 

  1. The following data is the total fat, in grams per serving, for a sample of 20 chicken sandwiches from fast-food chains. The data are as follows:

 

7     8     4     5     16     20     20     24     19     30

23   30   25   19     29     29     30     30     40     56

Source: Extracted from “Fast food: Adding Health to the Menu,” Consumer Reports, September 2004, pp. 28-31.

 

  1. Place the data into an ordered array.
  2. Construct a stem-and-leaf display.
  3. Does the ordered array or the stem-and-leaf display provide more information? Discuss.

 

 

  1. The following data represent the cost of electricity during July 2006 for a random sample of 50 one-bedroom apartments in a large city:

 

Raw Data Utility Charges ($)

 

96     171     202     178     147     102     153     197     127     82

157     185       90     116     172     111     148     213     130   165

141     149     206     175     123     128     144     168     109   167

95     163     150     154     130     143     187     166     139   149

108     119     183     151     114     135     191     137     129   158

 

  1. Form a frequency distribution and a percentage distribution that have class intervals with the upper class limits $99, $119, and so on. (Hint: It means that the first class can be expressed as $80 but less than $100, where $100 is not included in the first class but the second class.)
  2. Construct a histogram and a percentage polygon.
  3. Form a cumulative percentage distribution and plot a cumulative percentage polygon.
  4. Around what amount does the monthly electricity cost seem to be concentrated?