Stat 217 – HW 5

1) U.S. Census Debate – 7 pts

(a) Under Course Materials > Videos, watch “Daily Show: The Census” (or here)

(b) Then watch the “Clip from West Wing”

Note: There are sometimes technical issues in viewing these videos. Review some of the instructions under the Technology button but also be prepared to use a campus computer or PC. Leave yourself plenty of time!

(c) Answer the following questions.  Feel free to use other sources as well but be sure to cite them.

1) What is the goal of the US decennial census?

2) When is the next census to be conducted?

3) Why is this such a contentious issue?

4) While not clearly explained, how do you suppose statistical sampling would be used in this context?

5) What is one of the main arguments for using statistical sampling with the Census?

6) What is one of the main arguments against using statistical sampling with the Census?

7) Based on the little bit you have learned here, what is your opinion?

Extra Credit: What did the Supreme Court rule in 1999?

2) Generation M – 10 pts

(a) The generation of children raised in the 1990s and 2000s has been dubbed “Generation M” because of the impact of media on their lives. The Kaiser Family Foundation conducted an extensive study to quantify how much time teenagers spend with various types of media. They gathered data from what they describe as a “nationally representative sample” of 2032 teenagers. One finding was that 31% of the respondents had a computer in their bedroom.

(a) Define the parameter of interest in this study (in words).

(b) Are the technical conditions necessary for a “one-sample z-interval” met for this study (p. 315)? Be sure you justify your answers.

(c) Calculate and interpret a 95% confidence interval using these data. Feel free to use the Test of Significance Calculator applet but include a screen capture of your input and output.

(d) Report the margin of error of this study (that is, the half-width of the interval you calculated).

(e) Cut the sample size in half (n = 1016) and again determine the margin of error. How does it compare to your answer in (d)?

(f) A rough approximation for the margin of error (with 95% confidence) is simply 1/√n. Calculate this value for the sample sizes in (d) and (e) and compare this to the margin of errors. Does this approximation seem in the ball park?

3) Activity 15-10 (p. 304-5) – 12 pts

Your (labeled) sketches can either be by hand or with the Normal Probability Calculator applet.

4) Activity 15-17 (p. 307) - 4 pts