/*! 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.3.1 To study the long-term effects o... [FREE SOLUTION] | 91影视

91影视

To study the long-term effects of preschool programs for poor children, researchers designed an experiment. They recruited 123children who had never attended preschool from low-income families in Michigan. Researchers randomly assigned 62of the children to attend preschool (paid for by the study budget) and the other 61to serve as a control group who would not go to preschool. One response variable of interest was the need for social services for adults. In the past 10years, 38children in the preschool group and 49 in the control group have needed social services.4 1. Does this study provide convincing evidence that preschool reduces the later need for social services? Carry out an appropriate test to help answer this question.

Short Answer

Expert verified

From the given information, the probability is0.2061

Step by step solution

01

Given Information

It is given in the question that, from the previous exercise

Mean(p^1p^2)=0.10

Standard deviation(p^1p^2)=0.097

Does this study provide convincing evidence that preschool reduces the later need for social services?

02

Explanation

The probability thatp^1p^2is less than or equal to0.02can be computed as:

localid="1650435144025" P(p^1p^20.02)=P((p^1p^2)(p1p2)(p^1p^2)0.02(p1p2)(p^1p^2))=P(Z0.02(0.1)0.097)=P(Z>0.82)=0.2061

Therefore, the required probability is 0.2061

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

44. Tropical flowers Different varieties of the tropical flower Heliconia are fertilized by different species of hummingbirds.

Researchers believe that over time, the lengths of the flowers and the forms of the hummingbirds鈥 beaks have evolved to match each other. Here are data on the lengths in millimeters for random samples of two color varieties of the same species of flower on the island of Dominica:

(a) A Fathom dotplot of the data is shown below. Use the graph to answer these questions:

  • Are the centers of the two groups similar or different? Explain
  • Are the spreads of the two groups similar or different? Explain.

(b) Construct and interpret a 95% confidence interval for the difference in the mean lengths of these two varieties of flowers.
(c) Does the interval support the researchers鈥 belief that the two flower varieties have different average lengths? Explain.

A fast-food restaurant uses an automated filling machine to pour its soft drinks. The machine has different settings for small, medium, and large drink cups. According to the machine鈥檚 manufacturer, when the large setting is chosen, the amount of liquid dispensed by the machine follows a Normal distribution with mean 27ounces and standard deviation0.8ounces. When the medium setting is chosen, the amount of liquid dispensed follows a Normal distribution with mean 17ounces and standard deviation 0.5ounces. To test the manufacturer鈥檚 claim, the restaurant manager measures the amount of liquid in a random sample of 25cups filled with the medium setting and a separate random sample of 20cups filled with the large setting. Let x1-x2be the difference in the sample mean amount of liquid under the two settings (large 鈥 medium). Find the mean and standard deviation of the sampling distribution.

A better drug? In a pilot study, a company's new cholesterol-reducing drug outperforms the currently available drug. If the data provide convincing

evidence that the mean cholesterol reduction with the new drug is more than 10 milligrams per deciliter of blood (mg/dl) greater than with the current drug, the company will begin the expensive process of mass-producing the new drug. For the 14 subjects who were assigned at random to the current drug, the mean cholesterol reduction was 54.1mg/dlwith a standard deviation of 11.93mg/dl.For the 15 subjects who were randomly assigned to the new drug, the mean cholesterol reduction was 68.7mg/dlwith a standard deviation of13.3mg/dl.Graphs of the data reveal no outliers or strong skewness.

(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.

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.

At a baseball game, 42of 65randomly selected people report owning an iPod. At a rock concert occurring at the same time across town, 34of 52randomly selected people to report owning an iPod. A researcher wants to test the claim that the proportion of iPod owners at the two venues is different. A 90%confidence interval for the difference in population proportions is ( 0.154, 0.138). Which of the following gives the correct outcome of the researcher鈥檚 test of the claim?

(a) Since the confidence interval includes 0, the researcher can conclude that the proportion of iPod owners at the two venues is the same.

(b) Since the confidence interval includes 0, the researcher can conclude that the proportion of iPod owners at the two venues is different.

(c) Since the confidence interval includes 0, the researcher cannot conclude that the proportion of iPod owners at the two venues is different.

(d) Since the confidence interval includes more negative than positive values, the researcher can conclude that a higher proportion of people at the rock concert own iPods than at the baseball game.

(e) The researcher cannot draw a conclusion about a claim without performing a significance test.

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.