36-201 INTRODUCTION TO STATISTICAL REASONING

Assignment #3

                Due:  In Lab, Thurs Feb 4 and Fri Feb 5.

Be sure to write your name and SECTION on your paper.  

STAPLE, DO NOT PAPERCLIP OR FOLD/TEAR, YOUR PAGES TOGETHER.

1. Moore, 4.71 and 4.74, p. 274.

2. Moore, 4.78, p. 275.  In addition please use interpolation with 
   the 68-98-99.7 rule to answer the following questions:
    * Approximately what percentile is a Z-score of 1.5?
    * Approximately what percentile is a Z-score of 1.75?

3. Siegel and Morgan, problem 14, p. 157

4. Siegel and Morgan, problem 9, p. 165

5. Four situations are described below.

   (A) In each situtation, two variables are listed.  Say whether
       each one is quantitative or qualitative (you should have
       eight answers for this part).

   (B) In each situation, say which variable is the independent
       variable, and which one is the dependent variable.  If you 
       think we won't understand why you chose the way you did, give
       your reasoning.

      (i) A law school wants to study the relationship between LSAT
          scores (LSAT is a law school entrance exam) and students' 
          first-year GPA's.
 
     (ii) An anthropologist is studying the relationship between the 
          heights of fathers and the heights of sons.

    (iii) A meteorologist is studying changes in monthly temperature
          averages over the course of a year.

     (iv) A medical researcher randomly assigns patients (with their 
          permission of course!) who are depressed to either receiving 
          the drug lithium, or to simply talking about coping with 
          depression with a therapist each week, and after one year 
          compares their scores on a standard test of major depressive 
          disorder.

6. Siegel and Morgan, problem 9, page 571.  For part (c), use the 
   descriptors on pp. 520 through 532 of Siegel and Morgan in your 
   description.

7. Siegel and Morgan, problem 12, p 573.