BLS 315A  Understanding Statistics  Brewer  Fall 2000  UW-Bothell

Homework Assignment #3

All homework assignments must typed or legibly handwritten, and must show your name, the assignment number, course number, and the date clearly.  Show all your calculations and other work (including SDA output).  Homework is due at the beginning of class on the specified date.

Due Monday, October 30

Chapter exercises:

ch. 10: 3: 6, 9(a-c), 19

SDA tasks:

1. Using the GSS data, produce a crosstabulation between part/fulltime work (PARTFULL) and marital status (MARITAL) for women.  To do this, select the "Frequencies or crosstabulation" action once you've chosen the GSS as a data set to analyze, and click the "Start" button.  On the next page ("SDA Tables Program"), put "MARITAL" in the Row blank and "PARTFULL" in the Column blank, and enter "sex(2)" for the Selection Filter.  Put a check in Percentaging for the row (conditional) percentages (assuming that PARTFULL is the dependent and column variable).  Then hit the "Run the table" button to get the results.  Describe the differences in work status for the different categories of women.  Recode the MARITAL variable to compare currently married women with women not currently married (i.e., those in all other categories) [click on "Recoding Variables" at the top of the SDA Tables Program page if you need more information about this].  Redo the analysis with this new coding (you can also rearrange the table by hand if you run into trouble with SDA's recoding procedure).  Compute the RR and OR for working fulltime based on whether a woman is currently married, and interpret the results.

2. Pick two ordinal variables that you're interested in (from any data set).  Specify the survey, and the meaning of the variables.  Define the independent and dependent variables for your analysis.  Compute the relevant conditional percentages (depending on which you think should be the independent and dependent variables).  Examine the table carefully.  Indicate the direction of the relationship (and explain it in terms so that someone who hasn't taken this course would understand) and your impression of the strength of the relationship.