/*! 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.8 Explain why the conditions for u... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 10: Q.8 (page 622)

Explain why the conditions for using two-sample z procedures to perform inference about p1-p2are not met in the settings

In-line skatersA study of injuries to in-line skaters used data from the National Electronic Injury Surveillance System, which collects data from a random sample of hospital emergency rooms. The researchers interviewed 161 people who came to emergency rooms with injuries from in-line skating. Wrist injuries (mostly fractures) were the most common.6The interviews found that 53people were wearing wrist guards and 6of these had wrist injuries. Of the 108who did not wear wrist guards, 45had wrist injuries.

Short Answer

Expert verified

The two-proportion z-test is not appropriate in this case.

Step by step solution

01

Step 1: Given Information

It is given in the question that, x1=6,n1=53,x2=45,n2=108

02

Explanation

The values are:

x1=6,n1=53,x2=45,n2=108

To perform the two-proportion z -test, the number of successes in both samples must be more than 10.

Here, success in the first sample is 6which is less than 10. It implies that the normality assumption is not fulfilled here.

Hence, the two-proportion z-test is not appropriate in this case.

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

Which of the following is not a property of a binomial setting?

(a) Outcomes of different trials are independent.

(b) The chance process consists of a fixed number of trials,n

(c) The probability of success is the same for each trial.

(d) If we use a sample size of 30, the binomial distribution will be approximately Normal.

(e) Each trial can result in either a success or a failure.

Refer exercise 35.Suppose we select independent SRSs of 25men aged 20to 34and 36boys aged 14and calculate the sample mean heights xMand xB.

(a) Describe the shape, center, and spread of the sampling distribution ofxM-xB.

(b) Find the probability of getting a difference in sample means xM-xBthat鈥檚 less than0mg/dl. Show your work.

(c) Should we be surprised if the sample mean cholesterol level for the 14-year-old boys exceeds the sample mean cholesterol level for the men? Explain.

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" 伪=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.

One major reason that the two-sample t procedures are widely used is that they are quite robust. This means that

(a) t procedures do not require that we know the standard deviations of the populations.

(b) t procedures work even when the Random, Normal, and Independent conditions are violated.

(c) t procedures compare population means, a comparison that answers many practical questions.

(d) confidence levels and P-values from the t procedures are quite accurate even if the population distribution is not exactly Normal.

(e) confidence levels and P-values from the t procedures are quite accurate even if outliers and strong skewness are present

Starting in the 1970s, medical technology allowed babies with very low birth weight (VLBW, less than 1500grams, or about 3.3pounds) to survive without major handicaps. It was noticed that these children nonetheless had difficulties in school and as adults. A long study has followed 242randomly selected VLBW babies to age 20years, along with a control group of 233randomly selected babies from the same population who had normal birth weight.

(a) Is this an experiment or an observational study? Why?

(b) At age 20,179 of the VLBW group and 193 of the control group had graduated from high school. Is the graduation rate among the VLBW group significantly lower than for the normal-birth-weight controls? Give appropriate statistical evidence to justify your answer.
See all solutions

Recommended explanations on Math Textbooks

Theoretical and Mathematical Physics

Read Explanation

Mechanics Maths

Read Explanation

Probability and Statistics

Read Explanation

Pure Maths

Read Explanation

Logic and Functions

Read Explanation

Statistics

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.