Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 4: Q 43. (page 230)

Sleep debt (3.2)A researcher reported that the average teenager needs 9.3 hours of sleep per night but gets only 6.3hours.17By the end of a 5-day school week, a teenager would accumulate about 15 hours of “sleep debt.” Students in a high school statistics class were skeptical, so they gathered data on the amount of sleep debt (in hours) accumulated over time (in days) by a random sample of 25high school students. The resulting least-squares regression equation for their data is Sleepdebt⏜=2.23+3.17(days). Do the students have reason to be skeptical of the research study’s reported results? Explain.

Short Answer

Expert verified

Yes, students have reason to be dubious of the findings of the research investigation.

Step by step solution

01

Given information

Number of high school students, n=25

The resulting least-squares regression equation for their data is,Sleepdebt=2.23+3.17(days)

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

The following is the resultant least square regression line for the data supplied in the question:

sleepdebt⏜=2.23+3.17(days)Sˆ

Thus, we have to evaluate by replacing the days with

as: sleepdebt⏜=2.23+3.17(days)

=2.23+3.17(5)=18.08

As a result, the students have grounds to doubt the findings because their estimated sleep debt exceeds the study's sleep debt of 15 hours.

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.

Start your free trial

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

Online polls In June 2008, Parade magazine posed the following question: “Should drivers be banned from using all cell phones?” Readers were encouraged to vote online at parade.com. The July13,2008 issue of Parade reported the results: 2407(85%) said “Yes” and 410(15%) said “No.”

(a) What type of sample did the Parade survey obtain?

(b) Explain why this sampling method is biased. Is 85% probably higher or lower than the true percent of all adults who believe that cell phone use while

driving should be banned? Why?

Sampling frame Refer to the previous exercise. It is more common in telephone surveys to use random digit dialing equipment that selects the last four digits of a telephone number at random after being given the exchange (the first three digits). Explain how this sampling method results undercover which could lead to bias.

Fabric science A maker of fabric for clothing is setting up a new line to “finish” the raw fabric. The line will use either metal rollers or natural-bristle rollers to raise the surface of the fabric; a dyeing-cycle time of either 30 or 40 minutes; and a temperature of either 150° or 175° Celsius. An experiment will compare all combinations of these choices. Three specimens of fabric will be subjected to each treatment and scored for quality.

Internet telephone calls You can use Voice over Internet Protocol (VoIP) to make long-distance

telephone calls over the Internet. How will the cost affect the use of this service? A university plans an experiment to find out. It will offer the service to all 350 students in one of its dormitories. Some students will pay a low flat rate. Others will pay higher rates at peak periods and very low rates off-peak. The university is interested in the amount and time of use and inthe effect on the congestion of the network.

Got deodorant? A group of students wants to perform an experiment to determine whether Brand A or Brand B deodorant lasts longer. One group member

suggests the following design: Recruit 40student volunteers—20male and 20female. Separate by gender, since male and female bodies might respond

differently to deodorant. Give all the males Brand A deodorant and all the females Brand B. Have each student rate how well the deodorant is still working at the end of the school day on a 0 to 10 scale. 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 (a).
See all solutions

Recommended explanations on Math Textbooks

Discrete Mathematics

Read Explanation

Mechanics Maths

Read Explanation

Calculus

Read Explanation

Geometry

Read Explanation

Statistics

Read Explanation

Decision Maths

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.

Sign-up for free