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

Does music help or hinder memory? Many students at Matt’s school claim they can think more clearly while listening to their favorite kind of music. Matt believes that music interferes with thinking clearly. To find out which is true, Matt recruits 84 volunteers and randomly assigns them to two groups. The “Music” group listens to their favorite music while playing a “match the animals” memory game. The “No Music” group plays the same game in silence. Here are some descriptive statistics for the number of turns it took

the subjects in each group to complete the game (fewer turns indicate better performance):

Matt wants to know if listening to music affects the average number of turns required to finish the memory game for students like these.

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.

Short Answer

Expert verified

Part a) The hypotheses are:

H0:μ1=μ2Ha:μ1notequaltoμ2

Part b) All condtions are met.

Step by step solution

01

Part a) Step 1: Given information

The given claim is that a difference in the means.

02

Part b) Explanation

We must now determine the appropriate hypotheses for performing a significance test.

As a result, the claim represents either the null hypothesis or the alternative hypothesis. According to the null hypothesis, the population proportions are equal. If the claim is the null hypothesis, then the alternative hypothesis states the inverse of the null hypothesis.

Therefore, the appropriate hypotheses for this are:

H0:μ1=μ2Ha:μ1notequaltoμ2

μ1=the true mean number of turns required to complete the memory game for music-listening students.

For students who do not listen to music, μ2 is the true mean number of turns required to complete the memory game.

03

Part b) Step 1: Explanation

There are three requirements that must be met:

It is satisfying because the samples are drawn at random from different populations.

Independent: It is satisfying because the sample of 42people represents less than 10%of the total population.

Normal: It is satisfied because both samples are large, with sample sizes of at least 30.

As a result, all of the conditions are met, and a hypothesis test for the mean difference is appropriate.

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

Music and memory Refer to Exercise 87.

a. Construct and interpret a 99%confidence interval for the true mean difference. If you already defined the parameter and checked conditions in Exercise87, you don’t need to do them again here.

b. Explain how the confidence interval provides more information than the test in Exercise .

The power takeoff driveline on tractors used in agriculture is a potentially serious hazard to operators of farm equipment. The driveline is covered by a shield in new tractors, but for a variety of reasons, the shield is often missing on older tractors. Two types of shields are the bolt-on and the flip-up. It was believed that the boll-on shield was perceived as a nuisance by the operators and deliberately removed, but the flip-up shield is easily lifted for inspection and maintenance and may be left in place. In a study initiated by the US National Safety Council, random samples of older tractors with both types of shields were taken to see what proportion of shields were removed. Of 183tractors designed to have bolt-on shields, 35had been removed. Of the 156tractors with flip-up shields, 15were removed. We wish to perform a test of H0:pb=pfversus Ha:pb>pf, where pband pfare the proportions of all the tractors with bolt-on and flip-up shields removed, respectively. Which of the following is not a condition for performing the significance test ?

(a) Both populations are Normally distributed.

(b) The data come from two independent samples.

(c) Both samples were chosen at random.

(d) The counts of successes and failures are large enough to use Normal calculations.

(e) Both populations are at least 10times the corresponding sample sizes.

Men versus women The National Assessment of Educational Progress (NAEP)

Young Adult Literacy Assessment Survey interviewed separate random samples of840

men and 1077women aged 21to 25years.

The mean and standard deviation of scores on the NAEP’s test of quantitative skills were x1=272.40and s1=59.2for the men in the sample. For the women, the results were x ̄2=274.73and s2=57.5.

a. Construct and interpret a 90% confidence interval for the difference in mean score for

male and female young adults.

b. Based only on the interval from part (a), is there convincing evidence of a difference

in mean score for male and female young adults?

A random sample of 200New York State voters included 88Republicans, while a random sample of 300California voters produced141Republicans. Which of the following represents the 95%confidence interval for the true difference in the proportion of Republicans in New York State and California?

a. (0.440.47)±1.96((0.44)(0.56)+(0.47)(0.53)200+300)

b. (0.440.47)±1.96((0.44)(0.56)200+(0.47)(0.53)300)

c. (0.440.47)±1.96(0.44)(0.56)200+(0.47)(0.53)300

d. (0.440.47)±1.96(0.44)(0.56)+(0.47)(0.53)200+300

e. (0.440.47)±1.96(0.45)(0.55)200+(0.45)(0.55)300

A researcher wished to compare the average amount of time spent in extracurricular activities by high school students in a suburban school district with that in a school district of a large city. The researcher obtained an SRS of 60high school students in a large suburban school district and found the mean time spent in extracurricular activities per week to be 6hours with a standard deviation of 3hours. The researcher also obtained an independent SRS of 40high school students in a large city school district and found the mean time spent in extracurricular activities per week to be 5hours with a standard deviation of 2hours. Suppose that the researcher decides to carry out a significance test of H0: μsuburban=μcity versus a two-sided alternativ

The P-value for the test is 0.048. A correct conclusion is to

a. fail to reject H0because0.048<α=0.05. There is convincing evidence of a difference in the average time spent on extracurricular activities by students in the suburban and city school districts.

b. fail to reject H0because 0.048<α=0.05. There is not convincing evidence of a difference in the average time spent on extracurricular activities by students in the suburban and city school districts.

c. fail to reject H0because0.048<α=0.05. There is convincing evidence that the average time spent on extracurricular activities by students in the suburban and city school districts is the same.

d. reject H0because 0.048<α=0.05. There is not convincing evidence of a difference in the average time spent on extracurricular activities by students in the suburban and city school districts.

e. reject H0because 0.048<α=0.05 . There is convincing evidence of a difference in the average time spent on extracurricular activities by students in the suburban and city school districts.

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