Adapted from Statistical Reasoning for Everyday Life (Bennett, Briggs, & Triola,

Adapted from Statistical Reasoning for Everyday Life
(Bennett, Briggs, & Triola, 2017).
Understanding:
Application: 1. In a
Harris Interactive survey of 1006 adults, 86% say that they wash their hands
after using a public restroom; the margin of error is 3 percentage points. USA
Today reported that among 6028 adults observed in restrooms, 85% washed their
hands; the margin of error is 1 percentage point. Use the given statistics and
margin of error to identify the confidence interval for each study. Which study
do you believe, and why? 2. In a
survey of 1002 people, 701 (70%) said that they voted in the last presidential
election (based on data from ICR Research Group). The margin of error for this
survey was 3 percentage points. However, actual voting records show that only
61% of eligible voters cast a vote. Does this imply that people lied when
responding to the survey? Explain. 3. Describe
how you would apply the five basic steps in a statistical study to the
following research question: determine the percentage of drivers who text while
they are driving. 4. The
Journal of American Psychologists prints an article evaluating a new drug for
depression. The researchers who wrote the article received funding for their
labs from the pharmaceutical company that produces the drug. Is there a
potential for bias in this research study? How could it be avoided? Explain
your answer. 5. A college
dean obtains an alphabetical list of all full-time students at her college and
selects every 50th name on that list to survey those students regarding the
total amount of student loan debt that they will have upon graduating. She then
reports this average (mean) amount of debt among these students as the average
of all college students. What type of sample of this? What could she do to
improve her sample? 6. Explain
any problems likely to cause confounding, and suggest how they could be
avoided: in a comparison of gasoline with different octane ratings, 24 vans are
driven with 87 octane gasoline, and 28 SUVs are driven with 91 octane gasoline.
After each vehicle has been driven for 250 miles, the amount of gasoline
consumed is measured. 7. Explain
which of the 8 guidelines for evaluating a statistical study might be most
relevant: In a survey of 1,200 college students, each was asked whether they
are a good person. 8. The
following presents a headline in a local newspaper, as well as the story
summary. Discuss whether the headline accurately represents the story. Headline: “Drugs
Shown in 98% of Movies” Story Summary: A “government study” claims that drug use,
drinking, or smoking was depicted in 98% of top movie rentals (Associated Press).
9. What
crucial information is missing from the following “sound bite”? A USA Today
“Snapshot” reported that the percentage of people with diabetes who don’t know
that they have diabetes is “1 in 4.” The source was given as the American
Diabetes Association. 10. What
crucial information is missing from the following “sound bite”? CNN reports on
a Zagat survey of America’s top restaurants, which fund that “only 9
restaurants achieved a rare 29 out of a possible 30 rating, and none of these
restaurants are in the Big Apple.”