Archive for September 2018

XYZ Company claims to develop an additive which significantly improves gas mileage. Thirty participants were asked to drive first using a standard gasoline, and then drive using this gasoline with the additive. Data was collected for each participant's gas mileages. Which of the following Excel tests is appropriate to test the effectiveness of the additive?

Add Comment
XYZ Company claims to develop an additive which significantly improves gas mileage. Thirty participants were asked to drive first using a standard gasoline,...

Studies have suggested that compounds in broccoli might combat the effects of overexposure to ultraviolet radiation. We conduct an experiment to determine whether a cream consisting of a broccoli extract reduces sunburn pain. Sixty patients suffering from pain from severe sunburn are available. What is a good way to conduct the experiment?

Add Comment
Studies have suggested that compounds in broccoli might combat the effects of overexposure to ultraviolet radiation. We conduct an experiment to determine...

The National Institutes of Health is at last sponsoring proper clinical trials of some natural remedies. In one study at Duke University, 330 patients with mild depression are enrolled in a trial to compare Saint-John's-wort with a placebo and with Zoloft, a common prescription drug for depression. The Beck Depression Inventory is a common instrument that rates the severity of depression on a 0 to 3 scale. Identify the completely randomized clinical trial for this study.

Add Comment
The National Institutes of Health is at last sponsoring proper clinical trials of some natural remedies. In one study at Duke University, 330 patients...

The progress of a type of cancer differs in women and men. A clinical experiment to compare four therapies for this cancer therefore treats sex as a blocking variable. 500 male and 300 female patients have agreed to act as subjects. Which of the following approaches will you use to create a block design for the experiment?

Add Comment
The progress of a type of cancer differs in women and men. A clinical experiment to compare four therapies for this cancer therefore treats sex as a...

Researchers conducted an experiment to compare the effects of a carbohydrate-restricted diet (low-carb diet) and a calorie- and fat-restricted diet (low-fat diet) on weight loss. The researchers are concerned that the effect of diet may depend on gender, so sex is treated as a blocking variable. There are 122 severely obese individuals available for the study, 52 of whom are men and 70 of whom are women. Identify the most appropriate experiment design for the experiment.

Add Comment
Researchers conducted an experiment to compare the effects of a carbohydrate-restricted diet (low-carb diet) and a calorie- and fat-restricted diet...

A manufacturer of chisels is interested in determining how the angle at which the cutting edge is sharpened affects tool abrasion. To answer this question, engineers obtain 20 similar chisels. They sharpen five chisels at each of 22.5, 25, 27.5, and 30 degrees. Then, they measure the amount of abrasion (rated on a scale of 1 to 10, with 10 being the worst) after cutting several mortises (square holes) in 3/4-inch hard maple boards.

Add Comment
A manufacturer of chisels is interested in determining how the angle at which the cutting edge is sharpened affects tool abrasion. To answer this question,...

What is the preferred treatment for breast cancer that is detected in its early stages? The most common treatment was once removal of the breast. It is now usual to remove only the tumor and nearby lymph nodes, followed by radiation. To study whether these treatments differ in their effectiveness, a medical team examines the records of 25 large hospitals and compares the survival times after surgery of all women who have had either treatment.

Add Comment
What is the preferred treatment for breast cancer that is detected in its early stages? The most common treatment was once removal of the breast. It...

When the Current Population Survey asked the adults in its sample of 50,000 households if they voted in the 2000 presidential election, 55% said they had. The margin of error was less than 1%. But, as a matter of fact, only 51% of the adult population voted in that election. Why do you think the CPS result missed by much more than the margin of error?

Add Comment
When the Current Population Survey asked the adults in its sample of 50,000 households if they voted in the 2000 presidential election, 55% said they...

In a sample survey, the following question was asked: "Which of the following best represents your opinion on gun control? 1. The government should take away our guns. 2. We have the right to keep and bear arms. Identify the correct statement with reference to the survey question asked:

Add Comment
In a sample survey, the following question was asked: "Which of the following best represents your opinion on gun control?1. The government should take...

You want to investigate the attitudes of students at your school toward the school's policy on extra fees for lab courses. You have a grant that will pay the costs of contacting about 500 students. Assuming that budget is not a constraint, which of the following would be the most appropriate method of contacting the students?

Add Comment
You want to investigate the attitudes of students at your school toward the school's policy on extra fees for lab courses. You have a grant that will...

In October 2007, the Gallup Poll asked a sample of 1010 adults, "Are you in favor of the death penalty for a person convicted of murder?" The proportion who said they were in favor was 69%. Gallup says that the margin of error for this poll is ±3 percentage points. Suppose you want a margin of error half as large as estimated by Gallup. How many people must you plan to interview?

Add Comment
In October 2007, the Gallup Poll asked a sample of 1010 adults, "Are you in favor of the death penalty for a person convicted of murder?" The proportion...

A management student is planning a project on student attitudes toward part-time work while attending college. She develops a questionnaire and plans to ask 25 randomly selected students to fill it out. Her faculty adviser approves the questionnaire but suggests that the sample size should be increased to at least 100 students. Which of the following statements correctly identifies the relation between the margin of error for sample sizes of 100 and 25?

Add Comment
A management student is planning a project on student attitudes toward part-time work while attending college. She develops a questionnaire and plans...

A New York Times Poll on women's issues interviewed 1025 women randomly selected from the United States, excluding Alaska and Hawaii. The poll found that 47% of the women said they do not get enough time for themselves. The poll announced a margin of error of ±3 percentage points for 95% confidence in its conclusions. Which of the following statements is the correct confidence statement, in relation to the scenario?

Add Comment
A New York Times Poll on women's issues interviewed 1025 women randomly selected from the United States, excluding Alaska and Hawaii. The poll found...

A management student is planning a project on student attitudes toward part-time work while attending college. She develops a questionnaire and plans to ask 25 randomly selected students to fill it out. Her faculty adviser approves the questionnaire but suggests that the sample size should be increased to at least 100 students. Which of the following statements correctly explains the advantage of the larger sample?

Add Comment
A management student is planning a project on student attitudes toward part-time work while attending college. She develops a questionnaire and plans...

A November 2007 Gallup Poll of 1004 adults found that 572 are satisfied with the total cost they pay for their health care. The announced margin of error is ±3 percentage points. The announced confidence level is 95%. Which of the statements is a correct and complete confidence statement in this scenario?

Add Comment
A November 2007 Gallup Poll of 1004 adults found that 572 are satisfied with the total cost they pay for their health care. The announced margin of...

The BusinessWeek online poll is available at the BusinessWeek website. Visitors can simply click appropriate buttons to vote. In response to the question "Do you think Google is too powerful?" (March 27, 2007), 1336 said "Yes," 2051 said "No", and 335 said that they were not sure. What was the sample size for this poll?

Add Comment
The BusinessWeek online poll is available at the BusinessWeek website. Visitors can simply click appropriate buttons to vote. In response to the question...

Choosing at random is a "fair" way to decide who gets some scarce good, in the sense that everyone has the same chance to win. However, random choice isn't always a good idea. At times we don't want to treat everyone at the same because some people have a better claim. In which of the following situations, would you not prefer to choose at random?

Add Comment
Choosing at random is a "fair" way to decide who gets some scarce good, in the sense that everyone has the same chance to win. However, random choice...

In 2005 the San Francisco Bay Times reported on a poll in New Zealand that found that New Zealanders opposed the nation's new gay-inclusive civil-unions law by a 3-1 ratio. This poll was a call-in poll that cost $1 to participate in. The San Francisco Bay Times article also reported that a scientific polling organization found that New Zealanders favor the law by a margin of 56.4% to 39.3%. Which of the following statements is correct about the reliability of the polls?

Add Comment
In 2005 the San Francisco Bay Times reported on a poll in New Zealand that found that New Zealanders opposed the nation's new gay-inclusive civil-unions...

The BusinessWeek online poll is available at the BusinessWeek website. Visitors can simply click appropriate buttons to vote. In response to the question "Do you think Google is too powerful?" (March 27, 2007), 1336 said "Yes," 2051 said "No", and 335 said that they were not sure. Above the poll question, the following statement was mentioned: "Google's accelerating lead in search and its moves into software and traditional advertising are sparking a backlash among rivals." How might this statement affect the polls?

Add Comment
The BusinessWeek online poll is available at the BusinessWeek website. Visitors can simply click appropriate buttons to vote. In response to the question...

A university has 30,000 undergraduate and 10,000 graduate students. A survey of student opinion concerning health care benefits for domestic partners of students selects 300 of the 30,000 undergraduate students at random and then separately selects 100 of the 10,000 graduate students at random. The 400 students chosen make up the sample. Which of the following statements correctly explains why this sampling method gives each student an equal chance to be chosen?

Add Comment
A university has 30,000 undergraduate and 10,000 graduate students. A survey of student opinion concerning health care benefits for domestic partners...

A national survey of TV network news viewers found that 48% said they would believe a phone-in poll of 300,000 persons rather than a random sample of 1000 persons. Of the viewers, 42% said they would believe the random sample poll. Which of the following statements correctly explains why the opinions of only 1000 randomly chosen respondents are a better guide to what all people think than the opinions of 300,000 callers?

Add Comment
A national survey of TV network news viewers found that 48% said they would believe a phone-in poll of 300,000 persons rather than a random sample of...

Highway planners decided to make a main street in West Lafayette, Indiana, a one-way street. The Lafayette Journal and Courier took a one-day poll by inviting readers to call a telephone number to record their comments. The next day, the paper reported: "Journal and Courier readers overwhelmingly prefer two-way traffic flow in West Lafayette's Village area to one-way streets. By nearly a 7-1 margin, callers to the newspaper's Express Yourself opinion line on Wednesday complained about the one-way streets that have been in place since May. Of the 98 comments received, all but 14 said no to one-way." What population do you think the newspaper wants information about?

Add Comment
Highway planners decided to make a main street in West Lafayette, Indiana, a one-way street. The Lafayette Journal and Courier took a one-day poll by...

As part of a project for a political science class, a student decided to conduct an online poll. The student asked the following question: "Do you think that illegal immigrants should be allowed to pay instate tuition, even though they are not legal citizens of that state?" Possible responses were Yes, No, and Unsure. Of those who responded, 81% said No, 19% said Yes, and 0% said Unsure. Which of the following statements correctly explains the result of the poll with respect to reliability and bias?

Add Comment
As part of a project for a political science class, a student decided to conduct an online poll. The student asked the following question: "Do you think...

The BusinessWeek online poll is available at the BusinessWeek website. Visitors can simply click appropriate buttons to vote. In response to the question "Do you think Google is too powerful?" (March 27, 2007), 1336 said "Yes," 2051 said "No", and 335 said that they were not sure. Why do you think the poll may give unreliable information?

Add Comment
The BusinessWeek online poll is available at the BusinessWeek website. Visitors can simply click appropriate buttons to vote. In response to the question...

A manufacturer of chisels is interested in determining how the angle at which the cutting edge is sharpened affects tool abrasion. To answer this question, engineers obtain 20 similar chisels. They sharpen five chisels at each of 22.5, 25, 27.5, and 30 degrees. Then, they measure the amount of abrasion (rated on a scale of 1 to 10, with 10 being the worst) after cutting several mortises (square holes) in 3/4-inch hard maple boards. Which of the following is the explanatory variable in the given study?

Add Comment
A manufacturer of chisels is interested in determining how the angle at which the cutting edge is sharpened affects tool abrasion. To answer this question,...

A New York Times Poll on women's issues interviewed 1025 women randomly selected from the United States, excluding Alaska and Hawaii. The poll found that 47% of the women said they do not get enough time for themselves. The poll announced a margin of error of ±3 percentage points for 95% confidence in its conclusions. The confidence statement, in relation to the given scenario, is: "We are 95% confident that between 44% and 50% of all women would say that they do not get enough time for themselves." Which of the following statements correctly explains the meaning of the term '95% confidence', in the confidence statement?

Add Comment
A New York Times Poll on women's issues interviewed 1025 women randomly selected from the United States, excluding Alaska and Hawaii. The poll found...

A national survey of TV network news viewers found that 48% said they would believe a phone-in poll of 300,000 persons rather than a random sample of 1000 persons. Of the viewers, 42% said they would believe the random sample poll. Which of the following statements correctly explains why the opinions of only 1000 randomly chosen respondents are a better guide to what all people think than the opinions of 300,000 callers?

Add Comment
A national survey of TV network news viewers found that 48% said they would believe a phone-in poll of 300,000 persons rather than a random sample of...

Studies have suggested that compounds in broccoli might combat the effects of overexposure to ultraviolet radiation. We conduct an experiment to determine whether a cream consisting of a broccoli extract reduces sunburn pain. Sixty patients suffering from pain from severe sunburn are available. What is a good way to conduct the experiment?

Add Comment
Studies have suggested that compounds in broccoli might combat the effects of overexposure to ultraviolet radiation. We conduct an experiment to determine...

A researcher observes the body-mass index (BMI), the number of school meals eaten, and the sex for a sample of schoolchildren. The goal of the study is to determine the relationship between BMI and number of school meals, and whether this relationship depends on the child's sex. What type of study is this?

Add Comment
A researcher observes the body-mass index (BMI), the number of school meals eaten, and the sex for a sample of schoolchildren. The goal of the study...

In a weight-loss study, 10% of the subjects getting the experimental drug dropped out before the finish and 58% of the subjects getting the placebo dropped out. It is speculated that subjects in a weight-loss experiment may prematurely drop out when they find themselves not losing weight. This is an example of:

Add Comment
In a weight-loss study, 10% of the subjects getting the experimental drug dropped out before the finish and 58% of the subjects getting the placebo...

Consider an easy exam in which most of the students get scores between 90 and the maximum score of 100. A few get scores between 80 and 90, and even fewer get scores between 70 and 80, and just a couple get scores below 70. The histogram of scores on this exam would show a distribution that is

Add Comment
Consider an easy exam in which most of the students get scores between 90 and the maximum score of 100. A few get scores between 80 and 90, and even...

Refer to the histogram of the number of minority students, black, Hispanic, Native American, who earned doctorate degrees in engineering from 152 universities during 2000 to 2002. The classes for the histogram are 1-5, 6-10, and so on. Even without the actual data, you can use the position of the values of the five-number summary and the histogram to give the five-number summary approximately. About how many minority engineering PhD's must a university graduate to be in the top quarter?

Add Comment
Refer to the histogram of the number of minority students, black, Hispanic, Native American, who earned doctorate degrees in engineering from 152 universities...

Consumers are turning to trucks, SUVs, and minivans in place of passenger cars. The following is the data on sales of new cars and trucks in the United States (The definition of "truck" includes SUVs and minivans). Two line graphs are plotted on the same axes to compare the change in car and truck sales over time. Car sales are shown with the solid line graph and truck sales are shown with the dashed line graph. Which of the following statements correctly describes the trend displayed by the graph?

Add Comment
Consumers are turning to trucks, SUVs, and minivans in place of passenger cars. The following is the data on sales of new cars and trucks in the United...

A friend tells you, "In the 7:30 a.m. lecture for Statistics, 9 students failed. However, 20 students failed in the 1:30 p.m. class. The 1:30 p.m. professor is a tougher grader than the 7:30 a.m. teacher." Which of the following information will you require to conclude if 1:30 p.m. professor is a tougher grader than 7:30 a.m. professor?

Add Comment
A friend tells you, "In the 7:30 a.m. lecture for Statistics, 9 students failed. However, 20 students failed in the 1:30 p.m. class. The 1:30 p.m. professor...

Colleges announce an average SAT score for their entering freshmen. Usually a college would like this average to be as high as possible. A New York Times article noted, "Private colleges that buy lots of top students with merit scholarships prefer the mean, while open-enrollment public institutions like medians." Which of the following statements correctly explains these preferences?

Add Comment
Colleges announce an average SAT score for their entering freshmen. Usually a college would like this average to be as high as possible. A New York...
Pages 1 of 30 123NextLast
Subscribe to: Posts (Atom)