Stat 2000, Section 001, Homework Assignment 7 (Due 10/22/2001 11:59pm)

• 0) Reading: Sections 3.1, 3.2; Articles and info on statistical data on the Web
  
  
• 1) Please work on the following textbook questions in Moore/McCabe:
  
  
  • Exercise 3.3, 3.8, 3.9, 3.12, 3.13, 3.14, 3.15, 3.20 (1 Point each)
    
    
• 2) In this question, you have to locate statistical data on the Web. To obtain full points for each question, you have to indicate which steps you took to obtain the desired information, e.g., which search engine you used, which keywords you used in a search engine, which starting page you used, which intermediate pages you visited, and which links you followed. Also indicate the final URL(s) (i.e., the locations starting with http:// that show up in your Web browser) you think that are most suitable to answer a particular question. If you cannot locate a Web site that fully answers a question, indicate all steps you tried in locating such a site (and you should try at least two different approaches) to obtain full points. (10 Points)
  
  A search engine such as http://www.excite.com/, http://www.lycos.com/, or http://www.yahoo.com/ might be helpful to answer these questions. On top of these pages you usually have a box where you can type in the keywords you are looking for. You can type in a single keyword, multiple keywords separated by a blanc, e.g., kw1 kw2 kw3 (in this case, the search engine will look for kw1 or kw2 or kw3), and multiple keywords with a leading +, e.g., +kw1 +kw2 +kw3 (in this case, the search engine will look for kw1 and kw2 and kw3). If you try "text" where text appears in double quotes and may be a longer sentence, you should find pages that contain these words in exactly the same order (but eventually with a few other words inbetween).
  
  In addition to a search engine, or if you know that your data is likely to be distributed by a federal agency, use
  http://www.fedstats.gov
  as your starting point.
  
  
  • a) Locate a Web site that lists earthquakes in Utah since 1990.
    
    
  • b) Locate a Web site that deals with air pollution in Utah.
    
    
  • c) Locate a Web site that provides us with information on unemployment rates in Utah.
    
    
  • d) Indicate your major (or your area of specialization) and list at least 2 Web sites (i.e., their URLs) that distribute statistical data related to your major. These Web sites can contain data that typically is collected in your major, the number of graduates with this major that obtained a BS, MS, or PhD degree in 1999, summaries of salaries of people with this major in different US states or worldwide, or any other type of data related to your major. In this part (e) of the question, you do not have to indicate how you found the 2 Web sites. However, you have to explain in 2 or 3 sentences which kind of statistical data is available on each of the sites you listed.
    
    
• 3) Below is an excerpt from page 157 from Spirer, Spirer, and Jaffe's book "Misused Statistics" published by Marcel Dekker in 1998. What did the Literary Digest do wrong when sampling based on lists of automobile registrants, telephone directories, and similar sources? You should answer this with respect to the historical circumstances, not using todays standards. (3 Points)
  
  
  
  
• 4) This question is based on the four scatterplots below.
  
  
  The correct correlation coefficients for the data points displayed in these four scatterplots are 4 out of the following 6 values: -0.97, -0.72, -0.02, 0.50, 0.82, 0.97. For each plot, choose its correlation:
  • What is the correlation coefficient for Plot A?
    
  • What is the correlation coefficient for Plot B?
    
  • What is the correlation coefficient for Plot C?
    
  • What is the correlation coefficient for Plot D?
    
  Carefully explain why you assigned which correlation coefficient to which plot. (4 Points)