SUNY College at Buffalo Sociology 301 (Social Statistics)
Homework #4: To be due at the beginning of Chapter 5
Dr. ZHANG Jie

Submit your work on a Word file with the homework #, your name, and the date on top of it. You do not have to copy the questions, but the number of the question has to appear before your answer to each of them. The highest possible score for this homework is 10.

Essay Question 1:

How is Sigma X² different from (Sigma X)²?

Essay Question 2:

What is meant by the concept of variability?  What does standard deviation (s) mean?

Essay Question 3:

Describe the four measures of variability with their weaknesses and merits.  Why is variability important? In a normal distribution, what is the rough estimate of the standard deviation and why?

Essay Question 4:

Using a calculator, find the standard deviation of the following data:
1, 3, 4, 2, 3, 4, 5, 2, 1, 3, 5, 6, 1, 1, 2, 2, 3, 3, 3, 4, 4, 5, 5, 6
Make sure you have all the procedures on the paper to be submitted.

Computer Assignment:

Find a data set in the SPSS program and run its variability with different measures.  Please note that like the mean, variability can be requested only from a continuous variable (interval or ratio level).