Surveys, sampling method and categorical data

Chapter 3 & 4 Sample Problems

Chapter 3

5. GFK Roper Consulting conducts a global consumer survey to help multinational companies understand different consumer attitudes throughout the world. In India, the researchers interviewd 1000 people aged 13-65 . Their sample is designed so that they get 500 males and 500 females. a) Are they using a simple random sample? How do you know? b) What kind of design do you think they are using?

17. For your marketing class, you would like to take a survey from a sample of all the Catholic Church members in your city to assess the market for a DVD about the Pope's visit to the United States. A list of the Churches show 17 Catholic Churches within the city limits. Rather than try to obtain a list of all the members of all these Churches, you decide to pick three churches at random. For those Churches, you'll ask to get a list of all current members and contact 100 members at random. a) What kind of design have you used? b) What could go wrong with the design that you have proposed?

47. Sammy's Salsa, a small local company, produces 20 cans of salsa a day. Each case contains 12 jars and is imprinted with a code indicating the date and batch number. To help maintain consistency, at the end of each day, Sammy selects three bottles of salsa, weighs the contents, and taste the product. Help Sammy select the sample jars. Today's cases are coded 07N61 through 07N80. a) Carefully explain your sampling strategy. b) Show how to use random numbers to pick the three jars for testing. c) Did you use a simple random sample? Why?

Chapter 4

21. Cisco Systems Inc. announced plans in March 2007 to buy BebEx Communications Inc. for $3.2 billion, demonstrating their faith in the future of Web conferencing. The leaders in market share for the vendorsin the area of Web conferencing in 2006 were as follows: WebEx 58.4% and Microsoft 26.3%. Create an appropriate graphical display of this information and write a sentence or two that might appear in a newspaper article about the market share.

23. The Wells Fargo/Gallup Small Business Index asked asked 604 small business owners in October 2011 "how difficult or easy do you think it will be for your company to obtain credit when you need it?" 22% said "Very difficult," 21% "Somewhat difficult," 28% "About Average," 11% "Somewhat easy," and 11% "Very Easy." a) What do you notice about the percentage listed? How could this be? b) Make a barchart to display the results and label it clearly. c) Would a pie chart be an efficient way of communicating this information? Why or why not? d)

29. Google Inc. derives revenue from three major sources: advertising revenue from their websites, advertising revenue from thousands of third-party websites that comprise the Google network, and licensing and miscellaneous revenue. The following table shows the percentage of all revenue derived from these sources for the period 2007 to 20111. a) Are these rows or columns percentages? b) Make an appropriate display of these data. c) Write a brief summary of this information.

2007 2008 2009 2010 2011
Google Websites 64% 66% 67% 66% 69%
Google Network Member's Websites 35% 31% 30% 30% 28%
Other Revenues 1% 3% 3% 4% 3%