For Exercise 1.15, see page 9; for 1.16 and 1.17, see page 10, for 1.18 and 1.19, see pages 11-12; for 1.20 and 1.21, see page 15; for 1.22 and 1.23, see page 19; and for 1.24, see page 20.
1.25 Which graphical display should you use?
For each of the following scenarios, decide which graphical display (pie chart, bar graph, Pareto chart, stemplot, or histogram) you would use to describe the distribution of the variable. Give a reason for your choice and if there is an alternative choice that would also be reasonable, explain why your choice was better than the alternative.
1.25
(a) Histogram would be best to show the distribution. (b) Pareto chart would be the best to prioritize those characteristics that they liked best; pie chart might also be suitable. (c) A stemplot would be best because it is a small dataset; a histogram might also be suitable. (d) Pie chart is likely best in this situation to divide all the customers into groups from the whole; a Pareto or bar graph might also be suitable.
1.26 Garbage is big business.
The formal name for garbage is “municipal solid waste.” In the United States, approximately 250 million tons of garbage are generated in a year. Following is a breakdown of the materials that made up American municipal solid waste in 2012.11
garbage
Material | Weight (million tons) | Percent of total |
---|---|---|
Food scraps | 36.4 | 14.5 |
Glass | 11.6 | 4.6 |
Metals | 22.4 | 8.9 |
Paper, paperboard | 68.6 | 27.4 |
Plastics | 31.7 | 12.7 |
Rubber, leather | 7.5 | 3.0 |
Textiles | 14.3 | 5.7 |
Wood | 15.8 | 6.3 |
Yard trimmings | 34.0 | 13.5 |
Other | 8.5 | 3.4 |
Total | 250.9 | 100.0 |
1.27 Market share for desktop browsers
The following table gives the market share for the major search engines.12
browser
Search engine | Market share |
---|---|
Internet Explorer | 58.2% |
Chrome | 17.7% |
Firefox | 16.8% |
Safari | 5.7% |
Opera | 1.2% |
Other | 0.4% |
1.27
(b) Internet Explorer has by far the largest percentage of market share, followed by Chrome and Firefox. Other browsers have very little market share.
1.28 Reliability of household appliances.
You are writing an article for a consumer magazine based on a survey of the magazine’s readers. Of 13,376 readers who reported owning Brand A dishwashers, 2942 required a service call during the past year. Only 192 service calls were reported by the 480 readers who owned Brand B dishwashers.
1.29 Your Facebook app can generate a million dollars a month.
A report on Facebook suggests that Facebook apps can generate large amounts of money, as much as $1 million a month.13 The following table gives the numbers of Facebook users by country for the top 10 countries based on the number of users. It also gives the increases in the number of Facebook users for the one-month period from May 15, 2014, to June 15, 2014.14
facebk
Country | Facebook users (in millions) |
---|---|
Brazil | 29.30 |
India | 37.38 |
Mexico | 29.80 |
Germany | 21.46 |
France | 23.19 |
Philippines | 26.87 |
Indonesia | 40.52 |
United Kingdom | 30.39 |
United States | 155.74 |
Turkey | 30.63 |
1.29
(b) The United States is a clear outlier. They have 4 or 5 times as many Facebook users as the other countries, despite having a population smaller than some of the other countries. (c) The United States dominates; many other countries shown have similar amounts of Facebook users.
1.30 Facebook use increases by country.
Refer to the previous exercise. Here are the data for the increases in the number of Facebook users for the one-month period from May 15, 2014, to June 15, 2014.
facebk
Country | Increase in users (in millions) |
---|---|
Brazil | 2.47 |
India | 1.75 |
Mexico | 0.84 |
Germany | 0.51 |
France | 0.38 |
Philippines | 0.38 |
Indonesia | 0.37 |
United Kingdom | 0.22 |
United States | 0.65 |
Turkey | 0.09 |
1.31 Products for senior citizens.
The market for products designed for senior citizens in the United States is expanding. Here is a stemplot of the percents of residents aged 65 and older in the 50 states for 2012 as estimated by the U.S. Census Bureau American Community Survey.15 The stems are whole percents, and the leaves are tenths of a percent. Describe the shape, center, and spread of this distribution.
us65
8 | 5 |
9 | 5 |
10 | 9 |
11 | 58 |
12 | 1 |
13 | 00000222566788 |
14 | 0111134455567778889 |
15 | 0113478 |
16 | 08 |
17 | 0 |
18 | 2 |
1.31
The shape is symmetric, the center is around 14. The range is between 8.5 and 18.2.
1.32 The Canadian market.
Refer to Exercise 1.31. Here are similar data for the 13 Canadian provinces and territories:16
canadap
Province/territory | Percent over 65 |
---|---|
Alberta | 11.1 |
British Columbia | 15.7 |
Manitoba | 14.3 |
New Brunswick | 16.5 |
Newfoundland and Labrador | 16.0 |
Northwest Territories | 5.8 |
Nova Scotia | 16.6 |
Nunavut | 3.3 |
Ontario | 14.6 |
Prince Edward Island | 16.3 |
Quebec | 15.9 |
Saskatchewan | 14.9 |
Yukon | 9.1 |