Ch4 - Sample Quiz
Question 1.
Suppose we have a bivariate set of data with over 1000 sample
points. Which is not a valid value for r ?
a) 1
b) 2
c) -1
d) 0
e) None of the above
Question 2.
What does a value r = −.910 indicate?
a) Strong positive linear correlation
b) Moderate positive linear correlation
c) Strong negative linear correlation
d) No linear correlation
e) None of the above
Question 3.
If there is no linear correlation of the data, what value of r would
you most expect to see?
a) .589
b) -.432
c) .014
d) -.004
e) 1.000
Question 4.
What kind of correlation does the
scatter plot exhibit?
a) Negative linear
b) Positive linear
c) Positive Quadratic
d) Negative Quadratic
e) No correlation
Question 5.
What kind of correlation does the
scatter plot exhibit?
a) Negative linear
b) Positive linear
c) Positive Quadratic
d) Negative Quadratic
e) No correlation
Question 6.
What kind of correlation does the
scatter plot exhibit?
a) Negative linear
b) Positive linear
c) Positive Quadratic
d) Negative Quadratic
e) No correlation
Question 7.
For this scatter plot, what value
most closely represents the correlation coefficient?
a) -.823
b) .580
c) .261
d) .917
e) None of the above are close to the actual correlation
coefficient
Question 8.
The least-squares regression line seeks to minimize
a) the sum of the squared residuals, where a residual is the
difference between the observed y and the predicted y .
b) overall effort in calculating correlation.
c) the coefficient of determination.
d) the number of observations that do not lie on the line.
e) None of the above.
Question 9.
For a bivariate data set having a strong positive linear correlation,
which is true?
sx
a) The slope of the line is close to .
sy
b) The correlation coefficient is the y -intercept.
sy
c) The slope of the line is close to .
sx
d) The point (sx , sy ) lies on the line.
e) None of the above.
Question 10.
For any bivariate data set, which of the following is true?
a) The correlation coefficient r = 1 only when there is a strong
negative linear correlation.
b) The point (x̄, ȳ ) lies on the least squares regression line.
c) At least two points in the scatter plot lie on the least squares
regression line.
d) All of the above
e) None of the above
Question 11.
The coefficient of determination measures
a) how positive the linear relationship between the variables is.
b) how determined the relationship between the variables is.
c) how well the least squares regression line extrapolates beyond
the observed variables.
d) how well the least squares regression line describes the
relationship between the variables.
e) None of the above.