/*! 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. AP3.31 A researcher wants to determine ... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 10: Q. AP3.31 (page 705)

A researcher wants to determine whether or not a 5-week crash diet is effective over a long period of time. A random sample of 15five-week crash dieters is selected. Each person鈥檚 weight (in pounds) is recorded before starting the diet and 1year after it is concluded. Do the data provide convincing evidence that 5-week crash dieters weigh less, on average, 1year after finishing the diet?

Short Answer

Expert verified

The diet does not have a long-term effect.

Step by step solution

01

Step 1 -  Given information:

We have been given that:

Data of a 5-week crash diet.

02

Step 2 -  Explanation:

H0 is being tested: 渭b=渭aversus H1:渭b=渭a, where b is the mean of the before weights and an is the mean of the after weights The following table shows the changes between before and after weights: n=15 sample size,m=54/15=3

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

Ice cream For a statistics class project, Jonathan and Crystal held an ice-cream-eating contest. They randomly selected 29 males and 35 females from their large high school to participate. Each student was given a small cup of ice cream and instructed to eat it as fast as possible. Jonathan and Crystal then recorded each contestant鈥檚 gender and time (in seconds), as shown in the dot plots.

Do these data give convincing evidence of a difference in the population means at the 伪=0.103051526=0.200=20.0%伪=0.10 significance level?

a. State appropriate hypotheses for performing a significance test. Be sure to define the parameters of interest.

b. Check if the conditions for performing the test are met.

Have a ball! Can students throw a baseball farther than a softball? To find out, researchers conducted a study involving 24randomly selected students from a large high school. After warming up, each student threw a baseball as far as he or she could and threw a softball as far as he she could, in a random order. The distance in yards for each throw was recorded. Here are the data, along with the difference (Baseball 鈥� Softball) in distance thrown, for each student:

a. Explain why these are paired data.

b. A boxplot of the differences is shown. Explain how the graph gives some evidence that students like these can throw a baseball farther than a softball.

c. State appropriate hypotheses for performing a test about the true mean difference. Be sure to define any parameter(s) you use.

d. Explain why the Normal/Large Sample condition is not met in this case. The mean difference (Baseball鈭扴oftball) in distance thrown for these 24students is xdiff = 6.54yards. Is this a surprisingly large result if the null hypothesis is true? To find out, we can perform a simulation assuming that students have the same ability to throw a baseball and a softball. For each student, write the two distances thrown on different note cards. Shuffle the two cards and designate one distance to baseball and one distance to softball. Then subtract the two distances (Baseball鈭扴oftball) . Do this for all the students and find the simulated mean difference. Repeat many times. Here are the results of 100trials of this simulation

e. Use the results of the simulation to estimate the P-value. What conclusion would you draw ?

Which of the following describes a Type II error in the context of this study?

a. Finding convincing evidence that the true means are different for males and females when in reality the true means are the same

b. Finding convincing evidence that the true means are different for males and females when in reality the true means are different

c. Not finding convincing evidence that the true means are different for males and females when in reality the true means are the same

d. Not finding convincing evidence that the true means are different for males and females when in reality the true means are different

e. Not finding convincing evidence that the true means are different for males and females when in reality there is convincing evidence that the true means are different.

An agricultural station is testing the yields for six different varieties of seed corn. The station has four large fields available, located in four distinctly different parts of the county. The agricultural researchers consider the climatic and soil conditions in the four parts of the county as being quite different, but are reasonably confident that the conditions within each field are fairly similar throughout. The researchers divide each field into six sections and then randomly assign one variety of corn seed to each section in that field. This procedure is done for each field. At the end of the growing season, the corn will be harvested, and the yield (measured in tons per acre) will be compared. Which one of the following statements about the design is correct?

a. This is an observational study because the researchers are watching the corn grow.

b. This a randomized block design with fields as blocks and seed types as treatments.

c. This is a randomized block design with seed types as blocks and fields as treatments.

d. This is a completely randomized design because the six seed types were randomly assigned to the four fields.

e. This is a completely randomized design with24迟谤别补迟尘别苍迟蝉鈥�6 seed types and 4 fields.

Broken crackers We don鈥檛 like to find broken crackers when we open the package. How can makers reduce breaking? One idea is to microwave the crackers for 30seconds right after baking them. Randomly assign 65newly baked crackers to the microwave and another 65to a control group that is not microwaved. After 1day, none of the microwave group were broken and 16of the control group were broken. Let p1be the true proportions of crackers like these that would break if baked in the microwave and p2be the true proportions of crackers like these that would break if not microwaved. Check if the conditions for calculating a confidence interval forp1-p2met.
See all solutions

Recommended explanations on Math Textbooks

Discrete Mathematics

Read Explanation

Probability and Statistics

Read Explanation

Calculus

Read Explanation

Theoretical and Mathematical Physics

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.