CHAPTER TWO HOMEWORK
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.
A categorical variable has three categories with the following frequencies of occurrence:
Category Frequency
A
13
B
28
C
9
Compute the percentage of values in each category.
Construct a bar chart for percentage.
Construct a pie chart for percentage.
Construct a Pareto diagram.
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
Construct a bar chart, a pie chart, and a Pareto diagram.
Which graphical method do you think is best to portray these data?
Based on this survey, what conclusions can you reach about the use of the Internet at work?
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
Construct a bar chart and a pie chart for percentage.
Which graphical method do you think is best to portray these data?
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.
Place the data into an ordered array.
Construct a stem-and-leaf display.
Does the ordered array or the stem-and-leaf display provide more information? Discuss.
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
Form a frequency distribution and a percentage distribution that have class intervals with the upper class limits $99, $119, and so on.
Construct a histogram and a percentage polygon.
Form a cumulative percentage distribution and plot a cumulative percentage polygon.
Around what amount does the monthly electricity cost seem to be concentrated?
