Ed venture Time 02 (EZ SAT MATH)

A random sample of 100 female teachers was selected from all the female teachers in a school district. Each of the teachers selected was asked a survey question about an upcoming city ballot proposal. Of those surveyed, 42% responded yes to the question. What is the largest population to which the results of the survey can be generalized?

•  All adults in the city

  
  

• All adults in the city who are female

• All teachers in the school district

• All teachers in the school district who are female

 A psychologist designed and conducted a study to determine whether playing a certain educational game increases middle school students' accuracy in adding fractions. For the study, the psychologist chose a random sample of 35 students from all of the students at one of the middle schools in a large city. The psychologist found that students who played the game showed significant improvement in accuracy when adding fractions. What is the largest group to which the results of the study can be generalized?

• The 35 students in the sample 

  
  

• All students at the school

• All middle school students in the city

• All students in the city

 To determine the mean number of children per household in a community, Tabitha surveyed 20 families at a playground. For the 20 families surveyed, the mean number of children per household was 2.4. Which of the following statements must be true?

• The mean number of children per household in the community is 2.4.

  
  

• A determination about the mean number of children per household in the community should not be made because the sample size is too small.

• The sampling method is flawed and may produce a biased estimate of the mean number of children per household in the community.

• The sampling method is not flawed and is likely to produce an unbiased estimate of the mean number of children per household in the community.

A researcher wants to study the effect of a new math teaching method. She selects two groups of students: one group from an elite private school that uses the new method and another group from a public school using the traditional method. She then compares their test scores.

What is the main flaw in using this control group?

• The sample size is too small

• The control group has no baseline for comparison

• Differences between schools may affect the results

• The experimental group should not receive any instruction

Researchers in Australia carried out an experiment to determine if the color of a coffee mug affects how people rate the flavor intensity of the coffee. 

Volunteers were randomly assigned to taste coffee in mugs that differed only by color: some white and some clear. The same type of coffee was used in both mugs. The researchers concluded that the mean flavor intensity rating was significantly higher for those who drank coffee in a white mug than for those who drank coffee in a clear mug. Based on this study, which of the following statements is correct?

• The color of the mug was the cause of the difference in mean intensity rating for these volunteers, and this conclusion can be generalized to all coffee drinkers. 

• The color of the mug was the cause of the difference in mean intensity rating for these volunteers, but it is not reasonable to generalize this conclusion to all coffee drinkers.

• It is not reasonable to conclude that the color of the mug was the cause of the difference in mean intensity rating for these volunteers. 

• It is not possible to draw any conclusion from this experiment because volunteers were used.