Statistics Problem Set

  1. The original SAT was normed so that scores would be normally distributed, with a mean of 500, and a standard deviation of 100 points. If that is true, who portion of a sections test takers have scores: (hint: these will be easier if you draw a bell curve) 
    • Of 500 or higher?
    • Higher than 700?
    • Between 300 and 700?
    • EITHER higher than 700 or less than 300?
  2. Work with the US Macro data from previous weeks. You may want to destring the year and quarter variables if you have not done so already.
    • Standardize the GDP Growth variable (in other words calculate z-scores
      for each data point. What is the z-score for GDP in the 4th quarter of 2008? What does this z-score tell you about how extreme (or not extreme) GDP was in that quarter? Does this match what you would expect?
    • Create a 95 percent confidence interval for the unemployment rate variable. Write a sentence explaining what this confidence interval tells you.
    • Create a 95 percent confidence interval for the unemployment rate between 2007 & 2009. Write a sentence explaining what it means. Compare it to the confidence interval in part c- do your findings make sense given what you know about the world? 
MACRO DATA ATTACHED.
PLEASE INCLUDE ALL THE FORMULAS USED.