Practice Quiz: Chapter 1

1(points: 3) Briefly distinguish sampling error from nonsampling error. Which one represents avoidable mistakes? The other type can’t be eliminated, but what can you do to reduce it?

2(points: 3) “Of 2500 drivers surveyed, 10% said they got stuck in the snow this week.”
(a) Is this an example of descriptive or inferential statistics?
(b) Is the data type attribute, discrete, or continuous?

3(points: 3)  You’re conducting a survey on Tompkins County voters’ willingness to pay for expanded bus routes. You randomly select twenty bus trips on each day one week, and on each selected bus you hand a questionnaire to each person who gets on the bus.
(a) What is the most serious problem with this survey technique?
(b) What vocabulary word have we learned to describe the resulting sample?

4(points: 3)  “The average American household with children has 2.4 children.”
(a) Is this an example of descriptive or inferential statistics?
(b) Is the data type attribute, discrete, or continuous?

5(points: 3)  You want to test the effectiveness of a new medication for a condition that was previously untreatable. You randomly select thirty doctors from state lists of licensed doctors, and all of them agree to participate.

Each doctor will put up notices in the waiting rooms, and will select the first 30 adult volunteers, assigning the first 15 to the control group and the second 15 to the experimental group. Patients will not be told which group they are in; you supply placebo pills that are identical in appearance to the active medication. Doctors will administer the placebo and medication to the selected groups and report results back to you.

Name three serious errors in this technique. Are these examples of sampling or nonsampling error?