A113 Fall Semester 2002


Write your name or username here: ________________ Two hours, 40 points. Good luck and do well!


Problem (21 points - one per box)

Consider the formulas for the slope and intercept of the regression line:

and

Use them to compute the slope and intercept of the regression line for the following data:

 
xi yi
2 2        
4 4        
6 8        
8 6        
Sums (if needed)

Then verify your results with this picture.

Feel free to discuss your results, if you want.

Questions (19 points total)

  1. (3 points) What measures of central tendency have we studied this semester?

     
    
  2. (2 points) What measures of dispersion have we studied this semester?

     
    
  3. (3 points) What does the coefficient of correlation compute?

     
    
  4. (3 points) What is the purpose of the regression line?

     
    
  5. (3 points) What are the differences between the mode, median, and the arithmetic mean?

     
    
  6. (3 points) What does the covariance measure? Where do we use it? How?

     
    
  7. (2 points) What's the difference between the variance and standard deviation?