• Apple Stock Prices, 57
• Bishop, 50
• Browser Wars, 31, 35, 40
• Citydatr, 50
• Completion Times, 27, 42
• Currency Exchange Rates, 36, 40
• Earnings per Share, 40
• Exchange Rate, 55
• Finstad and Lie Study, 35
• Florin, 57
• Gold Price, 40
• Grade Point Averages, 46, 57
• HEI Cost Data Variable Subset, 28, 30, 35
• Housing Starts, 40
• Insurance, 32
• Inventory Sales, 55
• Macro 2009, 36, 37, 38, 40
• RELEVANT Magazine, 39, 57
• Returns, 50
• SAT Math, 53
• Shopping Times, 57
• Snappy Lawn Care, 57
• Stordata, 50
• Sun, 50
• Tennis, 34
• Water, 50 b. Graph the data with a time-series plot using
a vertical scale from 4,000 to 7,000.
c. Comment on the difference between these two time-series plots.
Application Exercises
1.49 The data file Exchange Rate shows an index of the value of the U.S. dollar against trading part-ners’ currencies over 12 consecutive months.
C
HAPTERE
XERCISES ANDA
PPLICATIONS Visit www.mymathlab.com/global or www.pearsonglobaleditions.com/newbold to access the data files.
1.51 Describe graphically the time (in hours) that 20 stu-dents studied for a statistics test.
6.5 5.8 4.5 6.2 4.8 7.3 4.6 3.9 4.4 5.5 5.2 6.7 3.0 2.4 5.0 3.6 2.9 4.0 2.8 3.6 1.52 A sample of 20 financial analysts was asked to
pro-vide forecasts of earnings per share of a corporation for next year. The results are summarized in the fol-lowing table:
Forecast ($ per share) Number of Analysts
9.95 6 10.45 2
10.45 6 10.95 8
10.95 6 11.45 6
11.45 6 11.95 3
11.95 6 12.45 1
a. Construct the histogram.
b. Determine the relative frequencies.
c. Determine the cumulative frequencies.
d. Determine and interpret the relative cumulative frequencies.
56 Chapter 1 Using Graphs to Describe Data
1.53 In one region it was found that 28% of people with in-comes less than $50,000 use the Internet; 48% of those with incomes between $50,000 to $74,999 use the Internet;
and 70% of those with incomes of at least $75,000 use the Internet. Use a pie chart or a bar chart to plot this data.
1.54 Regulatory agencies and the U.S. Congress are recog-nizing both the values and emerging issues for small firms as the Sarbanes-Oxley Act of 2002 (SOX) has been implemented. On April 23, 2006, the Advisory Committee on Smaller Public Companies issued a fi-nal report to the Security and Exchange Commission assessing the impact of SOX on smaller public compa-nies (Final Report 2006). A random sample of CEOs, CFOs, and board members of small, medium, and large firms were surveyed and their opinions of the overall impact of SOX on their firm were:
Impact of Sox Small Firms Medium Firms Large Firms
Little or no impact 17 13 6
Moderate to very major impact
13 41 22
Construct a cluster bar chart of these findings (Michel-son, Stryker and Thorne 2009).
1.55 A survey of consumers who had recently purchased their first smartphones sought to identify how much these consumers knew about using smartphone tech-nology. The findings were as follows: 90% could con-nect to the Internet, 80% could download an app, 55%
could use Bluetooth, 44% had set up their phones to receive e-mail, and 5% knew only how to make and re-ceive voice calls and texts. Present this data graphically.
1.56 A team of undergraduate business students was asked to recommend improvement to the data entry process at the county appraiser’s office. The team identified several types of errors, such as posting an incorrect name or entering an incorrect parcel number. The deed abstractors were asked to keep a record of the errors in data entry that were sent to them. The fol-lowing table is a frequency distribution of errors:
Defect Total
Posting error in name 23
Posting error in parcel 21
Property sold after tax bills were mailed 5 Inappropriate call transfer (not part of deeds>
mapping)
18 Posting error in legal description>incomplete
legal description
4 Deeds received after tax bills printed 6
Correspondence errors 2
Miscellaneous errors 1
a. Construct a Pareto diagram of these defects in data entry.
b. What recommendations would you suggest to the county appraiser?
1.57 Groupon, an online Web site, offers its subscribers at least one special deal per day to local businesses in their cities such as places to eat, health-related activities (spas or fitness centers), places to see (museums), a variety of
activities such as golfing or sky diving, or other specials (such as a Gap Groupon or a gourmet fruit basket). Since December 2008, the number of subscribers has increased from 400 to more than 50 million in more than 400 mar-kets, in over 40 countries (Groupon Hits 50m Subscribers, 2011). To date, Groupon claims that more than 30 mil-lion Groupons have been sold, saving subscribers nearly
$1.3 billion. From a survey of students at one university, it was found that during the past week, the following num-ber and category of Groupons were purchased: 230 (activ-ities); 80 (food); 90 (health-related items), and 50 (other).
a. Graph these purchases with a pie chart.
b. Graph these purchases with a bar chart.
1.58 For the random sample of Groupon purchases by the university students in Exercise 1.57, the following breakdown by gender was obtained:
Male Female Total
Activities 140 90 230
Food 45 35 80
Health related 20 70 90
Other 10 40 50
Total 215 235 450
a. Graphically depict the type of purchase by gender with a component bar chart.
b. Graphically depict the type of purchase by gender with a cluster bar chart.
1.59 What is the relationship between the $ price of paint and the gallon demand for this paint? A random sam-ple of (price, quantity) data for 7 days of operation was obtained. Construct a plot and describe the rela-tionship between quantity and price, with emphasis on any unusual observations.
110, 1002 18, 1202 15, 2002 14, 2002 110, 902 17, 1102 16, 1502
1.60 A consumer goods company has been studying the effect of advertising on total profits. As part of this study, data on advertising expenditures (1,000s) and total sales (1,000s) were collected for a 5-month period and are as follows:
110, 1002 115, 2002 17, 802 112, 1202 114, 1502 The first number is advertising expenditures and the second is total sales. Plot the data.
1.61 The president of Floor Coverings Unlimited wants in-formation concerning the relationship between retail experience (years) and weekly sales (in hundreds of dollars). He obtained the following random sample of experience and weekly sales:
12, 52 14, 102 13, 82 16, 182 13, 62 15, 152 16, 202 12, 42
The first number for each observation is years of expe-rience and the second is weekly sales. Plot the data.
1.62 A Malaysian swimming coach wanted to see if work-ing with a sports psychologist would improve the performance of elite swimmers. A random sample of 12 swimmers took part in the year-long program. The
Chapter Exercises and Applications 57 following ordered pairs show the number of sessions
each swimmer had with the psychologist and the cor-responding improvement in their personal best times (in seconds) for the 800-meter freestyle.
19, 2.42, 120, 5.62, 16, 1.82, 112, 4.12, 19, 2.12, 115, 4.82, 17, 2.32, 19, 4.32, 118, 6.22, 124, 7.12, 19, 1.52, 16, 2.22
Plot the data and state whether you think the program has been successful.
1.63 Four types of checking accounts are offered by one bank. Suppose that recently a random sample of 300 bank customers was surveyed and asked several ques-tions. It was found that 60% of the respondents pre-ferred Easy Checking; 12%, Intelligent Checking; 18%, Super Checking; and the remainder, Ultimate Checking.
Of those who selected Easy Checking, 100 were females;
one-third of the respondents who selected Intelligent Checking were males; half of the respondents who se-lected Super Checking were males; and 80% of respon-dents who selected Ultimate Checking were males.
a. Describe the data with a cross table.
b. Describe the data graphically.
1.64 How did people first learn about a new product? A ran-dom sample of 200 shoppers at a particular store was asked their age and whether they heard about the prod-uct from a friend or through a local newspaper adver-tisement. The results indicated that 50 respondents were under 21 years of age, 90 people were in the age group between 21 and 35, and 60 respondents were older than 35 years of age. Of those under 21 years old, 30 heard about the product from a friend, and the remainder learned about the product through an advertisement in the local paper. One-third of the people in the age cat-egory from 21 to 35 first learned about the product from the local newspaper advertisement; the remainder of this age group learned about the product from a friend.
A friend informed 30% of the people in the over-35 age category about the product; the remainder learned about it from the local newspaper advertisement.
a. Describe the data with a cross table.
b. Describe the data graphically.
1.65 A random sample of customers was asked to select their favorite soft drink from a list of five brands. The results showed that 30 preferred Brand A, 50 preferred Brand B, 46 preferred Brand C, 100 preferred Brand D, and 14 preferred Brand E.
a. Construct a pie chart.
b. Construct a bar chart.
1.66 The owner of Snappy Lawn Care thinks that the time it takes to mow a yard may be related to the temperatures at the time of mowing. He randomly sampled several yards of the same size and collected data on temperature and time it takes to mow. The data are in the data file Snappy Lawn Care. Plot the data with a scatter plot and comment on your findings.
1.67 Construct a time-series plot of population growth for the state of New York from 2002 to the present. (Hint:
Check www.census.gov.)
1.68 Florin, owner of Florin’s Flower Mart, ran-domly sampled 124 customers in order to ob-tain data such as a customer’s method of payment (Visa, MasterCard, American Express, cash, or some other method) and the day of the week that the cus-tomer made the purchase (except for when the store is closed on Sundays). The data are contained in the data file Florin. Construct the following:
a. A cross table of the variables method of payment and day of purchase
b. A pie chart of day of purchase
1.69 A random sample of 50 employees working for a large international bank in Hong Kong was interviewed to establish whether there was a link between the jobs of employees in the bank and where they normally ate at lunchtime—either in the canteen or at their desks. The results of this research showed that 75% of staff in cleri-cal roles normally ate in the office canteen and 54% of managers normally ate lunch at their desks. Compile a cross table and bar chart to display this information.
1.70 The closing costs of shares of Apple Inc. (AAPL) stock from January 3, 2011, through February 21, 2011, are contained in the data file Apple Stock Prices.
a. Construct a time series plot of the closing costs.
b. Obtain closing costs of Apple stock for the most recent 30-day period.
1.71 RELEVANT Magazine keeps records of traffic (such as the weekly number of new visitors) to its Web site from various social networks, such as Face-book and Twitter (Butcher 2011). Use a time-series plot to graph the number of unique page views by weekly new visitors to RELEVANT Magazine’s Web site by Facebook users over a recent 9-week period. The data are stored in the data file RELEVANT Magazine.
1.72 How much time (in minutes) do people spend on a typical visit to a local mall? A random sample of n = 104 shoppers was timed and the re-sults (in minutes) are stored in the data file Shop-ping Times.
a. Construct a histogram of these shopping times.
b. Construct a stem-and-leaf display of these shop-ping times.
1.73 The data file Grade Point Averages contains a random sample of 156 grade point averages for students at one university. Construct a stem-and-leaf display of the data.
1.74 A corporation administers an aptitude test to all new sales representatives. Management is interested in the extent to which this test is able to predict weekly sales of new representatives. Aptitude test scores range from 0 to 30 with greater scores indicating a higher aptitude. Weekly sales are recorded in hundreds of dollars. Construct a scatter plot of the following test scores and weekly sales for a random sample of 10 representatives.
Test Score, x 12 30 15 24 14 18 28 26 19 27 Weekly Sales, y 20 60 27 50 21 30 61 54 32 57
58 Chapter 1 Using Graphs to Describe Data