/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Q. T4.13 Google and Gallup teamed up to s... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 4: Q. T4.13 (page 291)

Google and Gallup teamed up to survey a random sample of 1673U.S. students in grades. One of the questions was 鈥淗ow confident are you that you could learn computer science if you wanted to?鈥� Overall, 54%of students said they were very confident.

a. Identify the population and the sample.

b. Explain why it was better to randomly select the students rather than putting the survey question on a website and inviting students to answer the question.

c. Do you expect that the percent of all U.S. students in grades 7鈥�12 who would say 鈥渧ery confident鈥� is exactly 54%? Explain your answer.

d. The report also broke the results down by gender. For this question, 62%of males and 48% of females said they were very confident. Which of the three estimates (54%,62%,48%)do you expect is closest to the value it is trying to estimate? Explain your answer.

Short Answer

Expert verified

The answer to these questions is:

a) Because not all samples were possible, it is not a simple random sample.
b) To account for hidden variables, one adult was picked at random.
c) This poll had several gaps in coverage. Those who did not have access to a telephone or who only had access to a cell phone were excluded from the study.
d) The survey results may not accurately reflect the views of the entire population.

Step by step solution

01

Part (a) Step 1: Given information

We have to identify the population and the sample.

02

Part (a) Step 2: Explanation

Because not all samples were possible, it is not a simple random sample. Given their strategy, they couldn't have gotten all of the responders from the East Coast, for example.

03

Part (b) Step 1: Given information

We have to tell why it was better to randomly select the students rather than putting the

survey question on a website.

04

Part (b) Step 2: Explanation

To account for hidden variables, one adult was picked at random. Perhaps those who frequently answer the phone have a different perspective than those who do not frequently answer the phone.

05

Part (c) Step 1: Given information

We have to tell who would say 鈥渧ery confident鈥� is exactly 54%

06

Part (c) Step 2: Explanation

There was under-coverage in this survey. Those who do not have telephones and those who have only cell phones were not part of the sampling frame, so their opinions were not measured. Since cell-honeonly users tend to be younger, the results of the survey may not accurately reflect the entire population鈥檚 opinions.

07

Part (c) Step 1: Given information

We have to tell about Which of the three estimates(54%, 62%, 48%) do you expect is closest to the value it is trying to estimate.

08

Part (d) Step 2: Explanation

There was under-coverage in this survey. Those who do not have telephones and those who have only cell phones were not part of the sampling frame, so their opinions were not measured. Since cell-honeonly users tend to be younger, the results of the survey may not accurately reflect the entire population鈥檚 \sopinions.

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 91影视!

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

A TV station wishes to obtain information on the TV viewing habits in its market area.

The market area contains one city of population 170,000, another city of70,000, and

four towns of about 5000residents each. The station suspects that the viewing habits

may be different in larger and smaller cities and in the rural areas. Which of the

following sampling designs would yield the type of information the station requires?

a. A stratified sample from the cities and towns in the market area

b. A cluster sample using the cities and towns as clusters

c. A convenience sample from the market area

d. A simple random sample from the market area

e. An online poll that invites all people from the cities and towns in the market area to

participate.

You wonder if TV ads are more effective when they are longer or repeated more often

or both. So you design an experiment. You prepare 30-second and 60-second ads for a

camera. Your subjects all watch the same TV program, but you assign them at random

to four groups. One group sees the 30-second ad once during the program; another sees

it three times; the third group sees the 60-second ad once; and the last group sees the

60-second ad three times. You ask all subjects how likely they are to buy the camera.

Which of the following best describes the design of this experiment?

a. This is a randomized block design, but not a matched pairs design.

b. This is a matched pairs design.

c. This is a completely randomized design with one explanatory variable (factor).

d. This is a completely randomized design with two explanatory variables (factors).

e. This is a completely randomized design with four explanatory variables (factors).

Got deodorant? A group of students wants to perform an experiment to determine

whether Brand Aor Brand Bdeodorant lasts longer. One group member suggests the

following design: Recruit 40student volunteers鈥�20male and20female. Separate by

gender, because male and female bodies might respond differently to deodorant. Give all

the males Brand Adeodorant and all the females Brand B. Have the principal judge how

well the deodorant is still working at the end of the school day on a 0to 10scale. Then

compare ratings for the two treatments.

a. Identify any flaws you see in the proposed design for this experiment.

b. Describe how you would design the experiment. Explain how your design addresses

each of the problems you identified in part (a).

Football on TVA Gallup poll conducted telephone interviews with a random sample of 1000adults aged 18and older. Of these, 37%said that football was their favorite sport to watch on television. The margin of error for this estimate is 3.1percentage points.

a. Would you be surprised if a census revealed that 50%of adults in the population would say their favorite sport to watch on TV is football? Explain your answer.

b. Explain how Gallup could decrease the margin of error

The administration at a high school with 1800 students wants to gather student opinions about parking for students on campus. It isn鈥檛 practical to contact all students.

a. Give an example of a way to choose a voluntary response sample of students. Explain how this method could lead to bias.

b. Give an example of a way to choose a convenience sample of students. Explain how this method could lead to bias.

c. Describe how to select an SRSof50students from the school.

d. Explain how the method you described in part (c) avoids the biases you described in parts (a) and (b).
See all solutions

Recommended explanations on Math Textbooks

Discrete Mathematics

Read Explanation

Probability and Statistics

Read Explanation

Applied Mathematics

Read Explanation

Mechanics Maths

Read Explanation

Decision Maths

Read Explanation

Geometry

Read Explanation
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.