Sleepless nights How much sleep do high school students get on a typical

school night? A counselor designed a survey to find out. To make data collection easier,

the counselor surveyed the first 100students to arrive at school on a particular morning.

These students reported an average of 7.2 hours of sleep on the previous night.

a. What type of sample did the counselor obtain?

b. Explain why this sampling method is biased. Is7.2hours probably greater than or less

than the true average amount of sleep last night for all students at the school? Why?

Short Answer

Expert verified

a) The subjects can decide whether or not they want to be included in the sample.A convenience sample is frequently text biased, because the fipersons will have slept less because they arrived earlier.

b) They have data about the strongest opinions, resulting.We estimate the average of 7.2hours to be less than the actual average.

Step by step solution

01

Part (a) Step 1: Given information

We have to tell about type of sample did the counsellor obtain.

02

Part (a) Step 2: Explanation

Because the student conveniently surveyed the first 100students, the sample in the activity prompt is a text convenience sample convenience sample. A convenience sample is frequently text biased, because the first100persons will have slept less because they arrived earlier, whereas students who arrived later will have slept longer.

03

Part (b) Step 1: Given information 

We have to tell about true average amount of sleep last night.

04

Part (b) Step 2: Explanation

A convenience sample is frequently textbfbiased, because the first 100persons will have slept less because they arrived earlier, whereas students who arrived later will have slept longer. We estimate the average of 7.2hours to be less than the actual average because the first 100students are likely to have slept less than the other pupils.

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

Sampling stuffed envelopes A large retailer prepares its customers’

monthly credit card bills using an automatic machine that folds the bills, stuffs them into

envelopes, and seals the envelopes for mailing. Are the envelopes completely sealed?

Inspectors choose 40envelopes at random from the 1000stuffed each hour for visual

inspection. Identify the population and the sample.

Can texting make you healthier? Researchers randomly assigned 700Australian adults

to either receive usual health care or usual heath care plus automated text messages with

positive messages, such as “Walking is cheap. It can be done almost anywhere. All you

need is comfortable shoes and clothing.” The group that received the text messages

showed a statistically significant increase in physical activity“statistically significant” in this context?

a. The results of this study are very important.

b. The results of this study should be generalized to all people.

c. The difference in physical activity for the two groups is greater than 0.

d. The difference in physical activity for the two groups is very large.

e. The difference in physical activity for the two groups is larger than the difference

that could be expected to happen by chance alone.

Do you trust the Internet? You want to ask a sample of high school students the question “How much do you trust information about health that you find on the Internet—a great deal, somewhat, not much, or not at all?” You try out this and other questions on a pilot group of 5students chosen from your class.

a. Explain how you would use a line of Table D to choose an SRS of 5students from the following list.

b. Use line 107to select the sample. Show how you use each of the digits.

Bias in a sampling method is

a. any difference between the sample result and the truth about the population.

b. the difference between the sample result and the truth about the population due to

using chance to select a sample.

c. any difference between the sample result and the truth about the population due to

practical difficulties such as contacting the subjects selected.

d. any difference between the sample result and the truth about the population that

tends to occur in the same direction whenever you use this sampling method.

e. racism or sexism on the part of those who take the sample.

Sampling the forestTo gather data on a 1200-acre pine forest in Louisiana, the U.S. Forest Service laid a grid of 1410equally spaced circular plots over a map of the forest. A ground survey visited a sample of 10%of the plots.

a. Explain how you would use a random number generator to choose an SRS of 141plots. Your description should be clear enough for a classmate to carry out your plan.

b. Use your method from part (a) to choose the first 3plots.

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