Stat 217 - HW 1

As soon as possible complete the following surveys (under Assignments > Surveys)

1) “SATS survey” in Blackboard (2 pts)

Try to answer as you would have before the first day of the course.

They will let me know whether or not you submit the survey but otherwise I will not see your answers until after the course and will never see your answers with your name.

2) “Stat 217 pre-test” in Blackboard(2 pts)

This will take about 30 minutes but gives me a sense for your background knowledge in statistics and will allow me to adjust our coverage accordingly.

3) “Stat 217 Questionnaire” in Blackboard (2 pts)

Note: This works best in browsers other than IE, but you can also add Blackboard to your list of trusted sites. See the instructions (and video demo) in Blackboard if you have trouble typing in your answers.

Advanced Warning

There will be one more survey on HW 2 that you may wish to take now. It will take about 5 minutes. Afterwards it will show you a webpage of your results which you should enter into the Blackboard “test” that has been created for this survey. Log into Blackboard, click the Assignments tab > Surveys, and follow the instructions for the “Learning Styles Survey”) there.

Reminders

Keep in mind if you get stuck on HW problems, you can email me, email the other students in the course, come by office hours, and/or use the Discussion Board to post questions/look for answers. I am notified when a new post is made and should get a response up within a few hours for others to see as well.

Also note that future homework assignments will not be printed out but can be retrieved from Blackboard under the Assignments menu button.

Assignment to be submitted at beginning of class Tuesday Jan. 12

· If you plan to turn in a hard copy

See the online course syllabus (under Course Materials) for formatting instructions, including: write on only the front side of each page and fold the pages lengthwise, putting your name, assignment number, and section number on the outside. Always staple all your pages together.

· If you plan to submit an electronic copy

You can email it to me: Make sure your name is clearly indicated in your email, in the file, and in the file name. You should use the subject line: Stat 217 HW submission.

Note: I encourage you to always replicate at least some portion the problem statement before each problem to aid your later review.

1) Surveys – 6 pts

2) Get Ready! – 3 pts

· Finish reading the syllabus. Ask any questions you have in class and/or email.

· In Blackboard, press the Technology button, and then follow the first link (“running this page”). This will let you know whether you should download any new programs or update any settings for using the pages we will want you to use this quarter.

· Under Course Materials, follow the link for Errata and make the corrections in the relevant locations in your text.

(a) What is the menu button you would use to find the outline of which activities we covered?

(b) What were the results when you ran the “test page” for the second bullet?

(c) What is the typo on p. 430, part c? What are the numbers given more correct than the ones currently given in the text?

3) Activity 1-7 parts (m), (n), (p), (q), (s), (t) (p. 11) – 6 pts

Hint: Make sure you identify both the variable type and the observational unit in each question.

4) Activity 1-5 (p. 8) – 6 pts

5) Activity 3-16 (p. 47) – 8 pts

Hint: In (d), state the number of people in the study. Then consider whether they used the same sampling method, but obtained a larger sample size. Would having a larger sample size necessarily change your opinion of the bias in the sampling method?

6) (6 pts) One of the early studies of the relationship between smoking and lung cancer was conducted by Hammond and Horn (1958). They and an extensive set of volunteers tracked 187,766 men over a 44-month period, nothing their smoking habits and whether or not they died of lung cancer.

(a) Identify the explanatory variable and the response variable in this study.

Hint: Make sure you state them as variables.

(b) Suppose a student argues that this was an observational study and identifies diet as a potential confounding variable. Provide a complete explanation of what would need to be true for diet to be a confounding variable and how it would therefore prevent us from drawing a cause-and-effect conclusion between smoking and lung cancer.

(c) Regardless of (b), the relationship between smoking and lung cancer found was very strong (smokers were about 13 times more likely to die from lung cancer than nonsmokers). Would you have any qualms about generalizing this relationship to the population of all adults? Explain.

Hint: That is, are you willing to say the relationship found among the men in this study convinces you that there is also a relationship in the larger population as well? Why or why not?