DATA 205
Lab Assignment 3: Dispersion
Run a frequency distribution table in SPSS for each variable (one at a time)and select the measure(s) of central tendency & dispersion that are possible for the type of measurement scale. Create a bar chart for each nominal or ordinal variable showing percentages. Create a histogram and a box plot using the Explore Command for each interval-ratio variable.
Refer to ‘Lab Instructions for Dispersion’ on BlackBoard for step by step instruction on how to run a frequency distribution table and how to create graphs in SPSS.
Answer the following questions for each variable:
1. What is/are possible measure(s) of dispersion?
2. If there is more than one measure of dispersion possible, what is the BEST measure and WHY. [Hint: What is the crudest measure? Is the frequency distribution highly skewed? Compare the mean and median to judge skewness.]
3. For each variable, summarize how much dispersion is found (high, moderate, low). [Hint: For nominal and ordinal measurement scales, look at percentage differences between categories. For interval-ratio measurement scales compare mean and median and look at box plot]
4. Include the tables (summary and frequency distribution table) here.
5. Include the bar chart or histogram here.
6. Include box plot here (ONLY for interval-ratio variable).
Variable 1: EDUC(Highest year of school completed)
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Variable 2: INCOME06(Total family income)
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Variable 3: REGION(Region of interview)
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