# Study Questions

### Chapter 4

The following data were drawn from the Latin American Migration Project, a collaborative research effort based at Princeton University and the University of Guadalajara, supported by the National Institute of Child Health and Human Development (NICHD) (http://lamp.opr.princeton.edu).

A random sample of respondents was drawn from three Latin American countries: Nicaragua, Guatemala, and Costa Rica. The variable if interest is the duration (in months) of stay in the United States during respondents' first migration to the United States.

Nicaragua: 4, 6, 6, 6, 12, 36, 36, 36, 36, 60, 72, 78, 96, 120, 126, 156, 162, 162, 186, 540
Guatemala: 1, 1, 12, 24, 24, 24, 36, 36, 42, 60, 78, 84, 102, 102, 102, 102,132, 144
Costa Rica: 12, 12, 12, 12, 14, 15, 15, 18, 18, 24, 36, 48, 66, 120, 150, 150, 174, 282, 288

1. Begin by specifying the level of measure for the variable of interest here. That is, what is the level of measurement of duration of stay during first U.S. migration?

2. Explain why the values of 12, 24, and 36 are so common in the data? What do these three values have in common?

3. Calculate the value of the mode for Costa Rica.

4. How does the mode for Guatemala compare to that of Costa Rica?

5. In light of your answers to Questions #3 and #4, perhaps one explanation is that respondents from Latin American countries that are closer to the United States have a higher modal duration of stay in the United States during their first U.S. migration than respondents from Latin American countries that are further away from the United States. Does the evidence from Nicaragua support this idea? (Hint: examine a map of Latin America to see whether you would expect the mode for Nicaragua to be greater than or less than that for Costa Rica and Guatemala.)

6. Given your results from Question #5, you are interested in extending this idea to the value of the median. Which country would you expect to have the highest median duration of stay in the United States during first U.S. migration?

7. Which of the three countries above in fact has the highest median value? Does this support your idea that respondents from Latin American countries that are closer to the United States have a higher median duration of stay in the United States during their first U.S. migration than respondents from Latin American countries that are further away from the United States?

8. At this point in your efforts, you notice that both Guatemala and Costa Rica have some very low and very high values? Which measure of central tendency is most susceptible to such extreme values?

9. Given your results from Questions #5 and #7, you are interested in extending the idea that respondents from Latin American countries that are closer to the United States have a higher mean duration of stay in the United States during their first U.S. migration than respondents from Latin American countries that are further away from the United States. Which country would you expect to have the lowest mean duration of stay during first U.S. migration?

10. Which of the three countries above in fact has the lowest mean duration? Does this support your idea that respondents from Latin American countries that are closer to the United States have a higher mean duration of stay in the United States during their first U.S. migration than respondents from Latin American countries that are further away from the United States?

11. For each country, identify the direction in which (if any) the distribution is skewed? Provide specific evidence using your answers from the previous questions.

12. Select one country from Question #11 and illustrate your conclusion graphically. On your graph, be sure to highlight the mode, median, and the mean.