Deck 12: Bivariate Correlation and Regression

Question 1

A graphical display of the strength of the relationship between two interval/ratio level variables is a ______.

A) histogram
B) box plot
C) scatterplot
D) pie chart

Answer 1

C

Question 2

After collecting data on age and number of speeding tickets, the researcher found that older people are less likely to have speeding tickets. What type of relationship is this between the two variables?

A) positive
B) linear
C) negative
D) nonlinear

Answer 2

C

Question 3

After collecting data on age and number of times one was victimized, the researcher found that older people are more likely to be victimized. What type of relationship is this between the two variables?

A) positive
B) linear
C) negative
D) nonlinear

Answer 3

A

Question 4

If one fit a line to their scatterplot and found that the line was flat, this would indicate what type of relationship?

A) positive
B) linear
C) negative
D) no relationship

Question 5

A statistic that quantifies the relationship between two interval/ratio level variables is ______.

A) Eta squared
B) Phi coefficient
C) Pearson correlation coefficient
D) Gamma

Question 6

A study found that the more elementary and junior high students are involved in structured after-school activities, the less likely they are to get involved with drugs. Which of the following correlations would reflect this relationship?

A) r = 1.00
B) r = .75
C) r = -.40
D) r = .00

Question 7

A correlation coefficient of .6 would indicate a ______.

A) moderate to strong positive relationship
B) weak to moderate positive relationship
C) moderate negative relationship
D) moderate positive relationship

Question 8

Which type of relationship between two variables does the Pearson correlation assume?

A) linear
B) significant
C) skewed
D) nonlinear

Question 9

The coefficient of determination is the square of the correlation coefficient. This informs one as to the ______.

A) critical value of the correlation
B) the proportion of the variation in dependent variable that is explained by the independent variable
C) the direction of the relationship
D) how strong the relationship is

Question 10

If a researcher obtains an r of .35, what would be the correct interpretation of r²?

A) 35% of the variation is explained
B) 45% of the variation is explained
C) 12% of the variation is explained
D) 80% of the variation is explained

Question 11

The mean is a statistic that ______.

A) makes the effect most likely
B) maximizes the variance
C) minimizes the variance
D) identifies the midpoint of the variance range

Question 12

The conditional mean of y is ______.

A) the means of y calculated at each value of x
B) the means of x calculated at each value of y
C) the total mean of y
D) the total mean of x

Question 13

The straight line that comes the closest to going through each conditional mean of y is the ______.

A) coefficient of determination
B) correlation coefficient
C) closest fitting line
D) best fitting line

Question 14

The estimation procedure ordinary least-squares (OLS) relies on is ______.

A) the squared deviations from the mean
B) raw deviations from the mean
C) standardized deviation from the mean
D) nonlinear deviations from the mean

Question 15

The y-intercept is the value when ______.

A) x is equal to its mean
B) x is equal to the mean of y
C) x is equal to 0
D) y is equal to 0

Question 16

In the regression equation β is the ______.

A) variable score
B) regression coefficient
C) constant
D) degrees of freedom

Question 17

The slope indicates ______.

A) the change in y associated with a one-unit change in x
B) the change in x associated with a one-unit change in y
C) how many units away from the mean of y x is
D) how many units away from the mean of x y is

Question 18

What would ŷ be if the intercept equals 12 and the b equals 2 for an x of 8?

A) 28
B) 22
C) 32
D) 20

Question 19

When outliers are included in the regression analysis, what is a likely outcome for the data?

A) The slope and correlation coefficients are not inflated.
B) The slope and correlation coefficients will remain unchanged.
C) The slope and correlation coefficients will be excessively influenced.
D) Only the slope coefficient will be excessively influenced while the correlation coefficient will not be influenced.

Question 20

Error in predicting the dependent variable is the ______.

A) type II error
B) type I error
C) residual
D) coefficient

Question 21

When the assumption of homoscedasticity is violated it means that ______.

A) the error terms are constant across all values of x
B) the error terms are not constant across all values of x
C) the residuals are too large
D) the residuals do not vary enough across values of x

Question 22

The y-intercept is where the regression line crosses the y-axis.

Question 23

The closer the data points are to the estimated regression line, the more accurate the predicted y scores are and the smaller the residuals will be.

Question 24

Both the regression slope coefficient and correlation coefficient are standardized and therefore its magnitudes do not depend on the measurement of the variables.

Question 25

What are the 5 assumptions for testing hypotheses of and . Describe each assumption.