/*! 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. 30 A sample survey interviews SRSs ... [FREE SOLUTION] | 91影视

91影视

A sample survey interviews SRSs of 500female college students and 550male college students. Each student is asked whether he or she worked for pay last summer. In all, 410 of the women and 484 of the men say 鈥淵es.鈥 The pooled sample proportion who worked last summer is about

(a) pC=1.70

(b)p^C=0.89

(c) p^C=0.88

(d) p^C=0.85

(e) p^C=0.82

Short Answer

Expert verified

The pooled sample proportion who worked last summer is option (c)p^C0.851.

Step by step solution

01

Given information

SRS of female college students =500

SRS of male college students =550

Number of women worked summer =410

Number of men worked summer =484

Find the pooled sample proportion who worked last summer.

02

Explanation

The given values are taken as

x1=410

n1=500

x1=484

n2=550

The proportion of pooled sample is

localid="1650360509081" p^C=x1+x2n1+n2=410+484500+550=89410500.85

p^C0.851.

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

Down the toilet A company that makes hotel toilets claims that its new pressure-assisted toilet reduces the average amount of water used by more than 0.5a gallon per flush when compared to its current model. To test this claim, the company randomly selects 30toilets of each type and measures the amount of water that is used when each toilet is flushed once. For the current-model toilets, the mean amount of water used is1.64a gal with a standard deviation of 0.29gal. For the new toilets, the mean amount of water used is 1.09galwith a standard deviation of 0.18gal.

(a) Carry out an appropriate significance test. What conclusion would you draw? (Note that the null hypothesis is notH0:1-2=0-

(b) Based on your conclusion in part (a), could you have made a Type I error or a Type Il error? Justify your answer.

A study of road rage asked separate random samples of 596men and 523women about their behavior while driving. Based on their answers, each re-spondent was assigned a road rage score on a scale of 0to 20. Are the conditions for performing a two-sample t test satisfied?

a) Maybe; we have independent random samples, but we need to look at the data to check Normality.

(b) No; road rage scores in a range between 0 and 20 can鈥檛 be Normal.

(c) No; we don鈥檛 know the population standard deviations.

(d) Yes; the large sample sizes guarantee that the corresponding population distributions will be Normal.

(e) Yes; we have two independent random samples and large sample sizes.

45. Paying for college College financial aid offices expect students to use summer earnings to help pay for college. But how large are these earnings? One large university studied this question by asking a random sample of 1296students who had summer jobs how much they earned. The financial aid office separated the responses into two groups based on gender. Here are the data in summary form:

(a) How can you tell from the summary statistics that the distribution of earnings in each group is strongly skewed to the right? A graph of the data reveals no outliers. The use of two-sample t procedures is still justified. why?
(b) Construct and interpret a 90%confidence interval for the difference between the mean summer earnings of male and female students at this university.
(c) Interpret the 90%confidence level in the context of this study.

Coaching and SAT scores (10.2) What we really want to know is whether coached students improve more than uncoached students and whether any advantage is large enough to be worth paying for. Use the information above to answer these questions:

(a) Is there good evidence that coached students gained more on average than uncoached students? Carry out a significance test to answer this question.

(b) How much more do coach students gain on the average? Construct and interpret a 99% confidence interval.

(c) Based on your work, what is your opinion: do you think coaching courses are worth paying for?

Researchers are interested in evaluating the effect of a natural product on reducing blood pressure. This will be done by comparing the mean reduction in blood pressure of a treatment (natural product) group and a placebo group using a two-sample t-test. The researchers would like to be able to detect whether the natural product reduces blood pressure by at least 7points more, on average than the placebo. If groups of size 50are used in the experiment, a two-sample t-test using role="math" localid="1650436089340" =0.01will have a power of 80%to detect a 7-point difference in mean blood pressure reduction. If the researchers want to be able to detect a 5-point difference instead, then the power of test

(a) would be less than 80%.

(b) would be greater than 80%.

(c) would still be 80%.

(d) could be either less than or greater than 80%, depending on whether the natural product is effective.

(e) would vary depending on the standard deviation of the data.

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.