Warning: foreach() argument must be of type array|object, bool given in /var/www/html/web/app/themes/studypress-core-theme/template-parts/header/mobile-offcanvas.php on line 20

Seat belt uses A study in El Paso, Texas, looked at seat belt use by drivers. Drivers were observed at randomly chosen convenience stores. After they left their cars, they were invited to answer questions that included questions about seat belt use. In all, 75% said they always used seat belts, yet only 61.5% were wearing seat belts when they pulled into the store parking lots.16 Explain the reason for the bias observed in responses to the survey. Do you expect bias in the same direction in most surveys about seat belt use?

Short Answer

Expert verified

It is not expected that all the surveys about the seat belt will be in the same direction.

Step by step solution

01

Given information

The use of seat belts by drivers was investigated in an EL Paso, Texas study. Drivers were monitored at convenience stores picked at random. They were asked to answer questions after getting out of their cars, including questions about seat belt use. Although75% of respondents indicated they always wear seat belts, only 61.5 percent were doing so when they pulled into the store parking lots.

02

Concept

A simple random sample (SRS) of size n is made up of n people chosen from the population with an equal chance of being the sample that is actually chosen.

03

Explanation

A selection bias or a non-response bias could occur. Most persons who do not wear seat belts are unlikely to tell you the truth. As a result, the results will be skewed, and the sample will not be representative of the full population. As a result, it is unlikely that all seat belt polls will point in the same way.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Cocoa and blood flowA study conducted by Norman Hollenberg, professor of medicine at Brigham and Womenโ€™s Hospital and Harvard Medical School,

involved 27healthy people aged 18-72. Each subject consumed a cocoa beverage containing 900milligrams of flavonols (a class of flavonoids) daily

for five days. Using a finger cuff, blood flow was measured on the first and fifth days of the study. After five days, researchers measured what they called โ€œsignifi-

cant improvementโ€ in blood flow and the function of the cells that line the blood vessels. What flaw in the design of this experiment makes it impossible to say

whether the cocoa really caused the improved blood flow? Explain.

A sampling at the mall You have probably seen the mall interviewer, approaching people passing by with a clipboard in hand. Explain why even a large sample of mall shoppers would not provide a trustworthy estimate of the current unemployment rate.

Call the shots A newspaper advertisement for an upcoming TV show said: โ€œShould handgun control be tougher? You call the shots in a special call-in

poll tonight. If yes, call 1-900-720-6181If not, call 1-900-720-6182A charge is 50 cents for the first minute.โ€ Explain why this opinion poll is almost certainly biased.

Sampling by accountants Accountants often use stratified samples during audits to verify a companyโ€™s records of such things as accounts receivable. The

stratification is based on the dollar amount of the item and often includes 100% sampling of the largest items. One company reports 5000 accounts receivable. Of these, 100 are in amounts over \(50,000;500 are in amounts between \)1000and\(50,000; and the remaining 4400are in amounts under \)1000Using these groups as strata, you decide to verify all the largest accounts and to sample 5% of the midsize accounts and 1%of the small accounts. How would you label the two strata from which you will sample? Use Table D, starting at line 115 to select only the first3 accounts from each of these strata.

The Web portal AOL places opinion poll questions next to many of its news stories. Simply click your response to join the sample. One of the questions

in January 2008 was โ€œDo you plan to diet this year?โ€ More than 30,000 people responded, with 68% saying โ€œYes.โ€ You can conclude that

(a) about 68% of Americans planned to diet in 2008

(b) the poll used a convenience sample, so the results tell us little about the population of all adults.

(c) the poll uses voluntary response, so the results tell us little about the population of all adults.

(d) the sample is too small to draw any conclusion.

(e) None of these.

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free