Stat 250, Section 701, Homework Assignment 2 (Due 6/1/98 in class)

• 0) As a review for the first quiz, you may want to work on these two exercises in Blaisdell (Second edition) (DO NOT TURN IN YOUR SOLUTIONS - ANSWERS ARE AT THE END OF THE TEXTBOOK):
  • Exercise 2.131, 2.132
  
  
• 1) Please work on the following textbook exercises in Blaisdell (Second edition):
  • Exercise 2.107, 2.109 a-d, 2.110
  • Exercise 2.114, 2.116, 2.118, 2.120, 2.121
  • Exercise 3.3 through 3.8, 3.9, 3.10, 3.19, 3.20
  • Exercise 3.23, 3.25
  
  
• 2) Look at "The Weather Page" from May 15, 1998 in USA Today. We took a random sample of 10 cities and got:
  
  Seattle (WA) 56/46
  Bismarck (ND) 73/47
  Richmond (VA) 83/57
  Raleigh (NC) 85/60
  Augusta (ME) 82/54
  Tulsa (OK) 85/62
  Tucson (AZ) 85/53
  Anchorage (AK) 53/42
  Denver (CO) 71/43
  Park City (UT) 54/31
  
  The first column indicates "forecast high", the second column is "tomorrow morning's low".
  
  • a) Draw a scatterplot of the data, plotting the "forecast high" on the (horizontal) x-axis and "tomorrow morning's low" on the (vertical) y-axis.
    
  • b) Describe the relationship you can see in the data.
    
  • c) Calculate SS(x), SS(y), SS(xy) for these 10 data points.
    
  • d) Determine the equation of the least squares line for this data.
    
  • e) Based on this equation, predict "tomorrow morning's lows" for given "forecast highs" of 60, 70, 85.
    
  • f) Would you use this equation to predict "tomorrow morning's low" for Nome (AK), knowing that the "forecast high" is 35? If so, which value do you get? And what is the predicted "tomorrow morning's low" according to USA Today? What happened?
  
  
• 3) This is an example from Mark Monmonier's book "How to Lie with Maps". The 4 graphics (maps) show the effect of selecting different class widths and starting points when visualizing data in a geographic context.
  
  
  • a) (i) If you were the governor of New York, which graphic would you use to demonstrate how advanced your state is?
    (ii) If you were the governor of Connecticut, which graphic would you use to demonstrate how advanced your state is?
    (iii) If you were the governor of New Jersey, which graphic would you use to demonstrate how advanced your state is?
    (iv) If you were the governor of Virginia, which graphic would you use to demonstrate how far behind your state is and desperately needs federal funding?
    (v) If you were a historician who wants to show how few telephones were around in 1960, which graphic would use?
    
    
  • b) Now find the "true" interval for the following 5 states. Do this by calculating the intersection of the class intervals used within the 4 graphics above:
    Maine
    New York
    Connecticut
    New Jersey
    Virginia
    
  • c) Describe your findings from b) in one or two sentences.
    
  • d) Now think of micromaps. Can you manipulate these as easily as these maps to express different political opinions? Explain. Describe how a micromap of this data might look like.