# MATHEMATICS

12. A study on the use of seat belts versus belted booster seats for children ages 4 and 5 reported that “Using seat belts instead of booster seats was associated with increased risk for serious injury in an accident; the relative risk was 2.4.” Based on this, it can be concluded that for this study:

A) The percent of children ages 4 and 5 in a booster seat was 2.4 times higher than the percent of children wearing seatbelts.

B) Children ages 4 and 5 in a booster seat were 2.4 times more likely to have serious injuries in an accident than were children wearing seatbelts

C) Children ages 4 and 5 wearing seatbelts were 2.4 times more likely to have serious injuries in an accident than were children in a booster seat.

D) The percent of children ages 4 and 5 wearing seatbelts was 2.4 times higher than the percent of children in a booster seat.

13. The relative risk of allergies for children of parents who smoke compared to children of parents who don’t smoke is 3.0. Suppose that the risk of allergies for the children of non-smokers is 0.15 (15%). What is the risk of allergies for the children of smokers?

A) 5%

B) 30%

C) 3%

D) 45%

14.Pick the choice that best completes the following sentence. If a relationship between two variables is called statistically significant, it means the investigators think the variables are

A) not related in the population represented by the sample.

B) related in the population represented by the sample.

C) related in the sample due to chance alone.

D) very important.

15.The table above shows the opinions of 953 respondents in the General Social Survey to the question “Everything considered, would you say that in general, you approve or disapprove of wiretapping?” The purpose of examining the data is to see if there is a gender difference in how people would respond to this question. State the null hypotheses for this study.

A) There is a relationship in the sample between gender and approval of wiretapping

B) There is no relationship in the sample between gender and approval of wiretapping

C) There is no relationship in the population between gender and approval of wiretapping

D) There is a relationship in the population between gender and approval of wiretapping

16.The table above shows the opinions of 1447 respondents in the General Social Survey to the question “Do you favor or oppose the death penalty for persons convicted of murder?” The purpose of examining the data is to see if there is a gender difference in how people would respond to this question. State the alternative hypotheses for this study.

A) There is a relationship in the sample between gender and opinion on the death penalty.

B) There is no relationship in the sample between gender and opinion on the death penalty.

C) There is a relationship in the population between gender and opinion on the death penalty.

D) There is no relationship in the population between gender and opinion on the death penalty.

17.If the correlation between a response variable Y and explanatory variable X is – 0.3, what is the value that defines how much variation in Y is explained by X?

A) – 9%

B) 9%

C) – 3%

D) 3%

18.Describe the type of association shown in the scatterplot above:

A) Positive linear association

B) Negative curvilinear association

C) Negative linear association

D) Positive curvilinear association

19.Which one of the following is not appropriate for studying the relationship between two quantitative variables?

A) Scatterplot

B) Bar chart

C) Regression

D) Correlation

20.In the simple linear regression equation y = b0 + b1x, the term b1 represents the

A) estimated slope.

B) estimated intercept.

C) estimated or predicted response.

D) explanatory variable.

21.Which of the following can not be answered from a regression equation?

A) Estimate whether the linear association is positive or negative.

B) Predict the value of y at a particular value of x.

C) Estimate whether the association is linear or non-linear

D) Estimate the slope between y and x.

22.A scatterplot above shows the price of a book (y variable) versus the number of pages in the book (x variable) is shown for 15 books in a professors office. In addition, the symbol “o” shows that the book was a hardcover book, while the symbol “+” shows that the book was a softcover book. What is the main difficulty with using a regression line to analyze these data?

A) Response variable is not quantitative

B) Presence of one or more outliers

C) Curvilinear data

D) Inappropriately combining groups

23.The value of a correlation is reported by a researcher to be r = – 0.5. Which of the following statements is correct?

A) The x-variable explains 50% of the variability in the y-variable.

B) The x-variable explains 25% of the variability in the y-variable.

C) The x-variable explains -25% of the variability in the y-variable.

D) The x-variable explains -50% of the variability in the y-variable.

24.From the regression output, what is the value of the correlation between Height and Weight?

A) – 0.612

B) 0.612 or – 0.612

C) 0.375

D) 0.612

25.Which variable in the Regression Equation represents the independent variable (also known as the predictor or explanatory variable)?

A) Weight

B) Height