1. The correlation in a large company between self-confidence and income is 0.25. After controlling for level of authority on the job, the original correlation dips to 0.11. What is this evidence of?

a) A direct relationship between self-confidence and incom

b) a spurious relationship between self-confidence and income; job authority causes both

c) an intervening relationship between self-confidence and income; self confidence affects income through increasing people's job auhority

d) either a spurious or an intevening relationship; it is impossible to differentiate the two possibilities on statisitcal grounds.

2. Consider the following multiple regression equation: Y= a+b₁X₁ + b₂X₂. What is the ideal correlation between X₁ and X₂, assuming that assumptions of multiple regression are fully met?

a) r=0

b) r=0.5

c) r=1

d) r=2

e) r=-1

3. A sociologist wishes to assess the association between two ordinal variables, both consisting of twelve categories. The researcher decides to collapse the categories into dichotomous form (categories 15 = "high" vs. categories 612 = "low") and then produce a bivariate table. Is this a good idea?

a) No, because the researcher is left with less powerful statistical tools: He/she can no longer use Cramer's v or phi to assess bivariate association.

b) No, because information is thrown away: The researcher must assume that different scores within the "high" or "low" categories are not meaningful.

c) Yes; measures for ordinal association cannot be used for variables with more than 10 variables.

d) Yes; if the researcher wishes to impose an arbitrary division point on a variable with many categories, it will greatly simplify the analysis.

Which of the following is a limitation of gamma?

a) It ignores pairs that are tied and can inflate the estimate of association.

b) It fails to tell us whether values of X help predict values of Y.

c) It is not on a clearly interpretable 0 to +1 scale like other measures of association.

d) t has a more complicated formula than Kendall's taub or Somers's d.

4. Consider a multiple regression equation predicting life expectancy in a random sample of 35 countries. X₁ is per capita GDP and X₂ is country's homicide rate (per 100,000). Suppose the regression equation is Y = a + 0.5(X₁) .08(X₂). How should we interpret a?

a) It is the predicted life expectancy value when a country has a GDP of 0 and a homicide rate of 0.

b) It is the predicted life expectancy value for a country with an averagelevel GDP and an average homicide rate.

c) It is the partial correlation between GDP and homicide rate.

d) Interpret it how you like, I am going on vacation.

5. Zoey has noticed that the correlation between presence of Izzy and her favorite toy (Mr. Hedgehog) going missing is 0.99. What can she conclude from this discovery?

a) Izzy is stealing Mr. Hedgehog

b) Presence of Izzy is not related to disappearance of Mr. Hedgehog

c) Presence of Izzy is somehow related to disappearance of Mr. Hedgehog

d) Izzy's presence is only contributing factor to disappearance of Mr. Hedgehog

e) Izzy's presence is the cause of disappearance of Mr. Hedgehog

6. What can be concluded if the betaweight of the first independent (X₁) is 0.45 and the betaweight of the second independent (X₂) is -0.50?

a) X2 has a stronger direct effect than X1

b) Y2 must equal zero

c) The multiple correlation coefficient must be negative

d) X1 has a stronger direct effect than X2

7. Researchers are interested in the relationship between number of hours played Pokmon Go in relation to age and level of education. They find that the following is true: Mean number of hours played Pokmon Go in one week was 5.7 hours (Mean of Y=5.7) with standard deviation of 2.6. The mean age of the sample was (Mean of X₁ =20) with standard deviation of 2.1. the mean number of years of education was 10.5 years (Mean of X₂ =10.5) with standard deviation of 0.45. Assume the following is true: r_y1= 0.7, r_y2= 0.30, r₁₂ = 0.55, b₁ = 0.65, b₂= -0.07, b*₁=0.46, b*₂= 0.05. Which of the following is true?

a) Hours played Pokmon Go increases as the person's age increases

b) Hours played Pokmon Go decreases as the person's age decreases

c) Hours played Pokmon Go increases as the persons' age decreases

d) Hours played Pokmon Go decreases as the person's age increases.

8. A theory suggests that X should have a positive effect on Y. Upon analysing a set of data, the correlation between X and Y is 0.55, and remains just as strong when Z is controlled. What does this tell us about the theory in question?

a) the theory was on the right track, but had the direction of the effect reversed.

b) the theory is proven correct.

c) The theory is supported, but other control variables need to be considered.

d) Nothing can be learned about the theory.

9. Seven students are part of a study. The independent variable is the amount of time they spent studying (Little, Moderate, Significant) and the dependent variable is their academic achievement (Low, Moderate, and High). How many unique pairs should the investigator use for calculating Kendall's tau-b?

a) 3

b) 6

c) 14

d) 21

e) 26

10. X has a causal influence on Y, even after Z is controlled. What is the term for this relationship between X and Y?

a) Partial correlation relationship

b) Direct relationship

c) Spurious relationship

d) Intervening relationship

11. Which of the following describes the slope (b) if a regression line is parallel to the horizontal axis of the scattergram?

a) 1.00

b) 0.5

c) 0

d) -1.00

e) -0.5