Which inference procedure?

A random sample of 1,092 people were asked whether color was a consideration in buying a new car. They were also asked to identify one additional feature that was important. The responses are shown in the table. Is there evidence to show a relationship between importance of color and which additional features are important?

• Two Sample t-test

• Chi-Square Goodness of Fit Test

• Chi-Square Test for Independence

• T-Test for Slope of a Regression Model

A research organization reported that 41 percent of adults who were asked to describe their day responded that they were having a good day rather than a typical day or a bad day. To investigate whether the percent would be different for high school students, 600 high school students were randomly selected. When asked to describe their day, 245 students reported that they were having a good day rather than a typical day or a bad day. Do the data provide convincing statistical evidence that the proportion of all high school students who would respond that they were having a good day is different from 0.41 ?

• Hypothesis Test for a Population Proportion

• Hypothesis Test for the Difference of Two Proportions

• Hypothesis Test for a Population Mean

• Hypothesis Test for a Matched Pair

Tags

CCSS.HSS.IC.B.4

To investigate whether the consumption of beetroot juice enhances exercise performance, a researcher selected a random sample of 50 student athletes from all the student athletes at a college. The athletes in the sample were randomly assigned to one of two groups. In one group, 25 athletes were given a daily dose of beetroot juice, and in the other group, the remaining athletes were given a daily dose of a placebo. At the end of six weeks of exercise training, the researcher compared the performances of the two groups.

• Two Sample T-Test

• Two Sample T-Interval

• Matched Pair T-Test

• Matched Pair T-Interval

Tags

CCSS.HSS.IC.B.4

Two high schools have a similar number of students and parking lots of similar size. The safety officers at both schools want to investigate whether there is an average difference in the number of cars parked per day in the student parking lots for the school year. A random sample of 15 school days will be selected. For each selected day, the number of cars parked in the student parking lots will be counted at both schools and the difference will be recorded. Assuming all conditions for inference are met, which of the following is the appropriate test for the investigation?

• A two-sample z-test for a difference between proportions

• A two-sample t-test for a difference between means

• A matched-pairs t-test for a mean difference

• A chi-square test of independence

A fitness center offers a one-month program designed to reduce body fat through exercise. The table shows the body fat percentage before and after completing the program for 10 randomly selected participants.

The director of the program wants to investigate whether knowing the body fat percentage before beginning the program can help to predict body fat percentage for someone who completes the program. Which of the following procedures is the most appropriate for such an investigation?

• Matched-Pairs t-test for a mean difference

• Two-sample z-test for a difference between proportions

• Chi-square test for independence

• t-test for slope of a linear regression model

Tags

CCSS.8.SP.A.3

The marketing director for an ice cream company investigated whether there was a difference in preference for two new ice cream flavors—cotton candy and mango. Each participant from a large group of people was randomly assigned to taste one of the two flavors. After tasting, each person rated the flavor on a numerical scale from 1 to 5, where 1 represented strongly dislike and 5 represented strongly like. What kind of interval would best describe the difference between means (cotton candy minus mango)?

• One sample t-interval

• Matched Pairs t-interval

• Two proportion z-interval

• Two sample t-interval

The director of a marketing department wants to estimate the proportion of people who purchase a certain product online. The director plans to obtain a random sample of 2,5002,500 people who purchased the product. Which inference procedure should she use to make this estimate?

• 1-proportion Z-interval

• 1-proportion Z-test

• Chi-Square Goodness of Fit Test

• Chi-Square Test for Homogeneity

Tags

CCSS.HSS.IC.B.4

A national health study reported that the proportion of students with elevated blood pressure is 0.15. The principal of a local high school believes that the proportion of students in the school with elevated blood pressure is greater than 0.15. If a large random sample is used, which of the following is the most appropriate test to investigate the principal’s belief?

• Z-test for a proportion

• Z-test for a difference between two proportions

• Chi-square test for homogeneity

• Matched-pairs t-test

Measuring the height of a tree is usually more difficult than measuring the diameter of the tree. Therefore, many researchers use regression models to predict the height of a tree from its diameter measured at 4 feet 6 inches from the ground. The following computer output shows the results of a linear regression based on the heights, in feet, and the diameters, in inches, recorded from 31 felled trees. What inference procedures could you use to establish if the regression model has predictive power?

• Chi-Square Test for Independence

• Chi-Square Test for Homogeneity

• T-interval for slope of a regression model

• T-test for slope of a regression model

A polling organization surveyed 2,002 randomly selected adults who are not scientists and 3,748 randomly selected adults who are scientists. Each adult was asked the question, “Do you think that genetically modified foods are safe to eat?” Of those who are not scientists, 37 percent responded yes, and of those who are scientists, 88 percent responded yes. How would you estimate the difference in proportion of all adults who are not scientists and all adults who are scientists who would answer yes to the question?

• Two proportion Z-interval

• Matched Pairs Interval

• Two sample t-interval

• One proportion Z-interval

Tags

CCSS.HSS.IC.B.4