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Chapter 4: Q 3.3. (page 244)

In an interesting experiment, researchers examined the effect of ultrasound on birth weight. Pregnant women participating in the study were randomly assigned to one of two groups. The first group of women received an ultrasound; the second group did not. When the subjects’ babies were born, their birth weights were recorded. The women who received the ultrasounds had heavier babies.

Based on your answers to Questions 1 and 2, describe an improved design for this experiment

Short Answer

Expert verified

It would have produced unbiased results.

Step by step solution

01

Given information

Pregnant women participating in the study were randomly assigned to one of two groups.

02

Concept

A placebo is an inactive treatment, sometimes called a 'sugar pill.

In a double-blind experiment, neither the subjects nor the people who interact with them and assess the response variable are aware of the treatment they received.

03

Explanation

Based on the facts provided, it is determined that the Placebo and double-blind studies should be considered. It would have yielded objective results.

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Most popular questions from this chapter

Students as customers A high school student the newspaper plans to survey local businesses about the importance of students as customers. From telephone book listings, the newspaper staff chooses 150 businesses

at random. Of these, 73 return the questionnaire mailed by the staff. Identify the population and the sample.

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(a) Which of the following best represents your opinion on gun control?

1. The government should confiscate our guns.

2. We have the right to keep and bear arms.

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weapons now and reduce the possibility of nuclear war in the future. Do you agree or disagree?

sampling all listed residential telephone numbers in the United States. Of 45,956 calls to these numbers, 5029 were completed. The goal of the survey was to estimate how far people drive, on average, per day.14

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