WGU C955 - Module 6: Correlation &
Regression Exam Questions and Answers
A researcher wants to know if there was a relationship between student age
and desire to complete a college degree. To answer this question, the
researcher used a local community college as the sampling frame and then
used stratified sampling to get a sample of students from 18 to 80 years old.
Based on the information given, is there any potential bias in this study?
a Yes, because the sampling frame does not match the intended population
of the question.
b Yes, because the sampling method will not give a representative sample.
c Yes, because a voluntary sample should have been used.
d No, there will likely be no bias in this study. - -Yes, because the sampling
frame does not match the intended population of the question.
-A researcher conducts an observational study and finds a correlation
between managers' income and the number of college credits earned. The
correlation coefficient was r=.85 with a regression equation of
y=515x+12000. What can you say about the relationship between these
variables?
a There is an association between these variables
b There is a causation between these variables.
c There is no relationship between these variables.
d There is not enough information to determine the relationship between the
variables. - -There is an association between these variables
-What technique is used to estimate the profit margin for a production level
of 25 thousand units, if a line of best fit is created to estimate profit margin
for production levels between 20 to 39 thousand units?
a Interpolation
b Linearization
c Extrapolation
d Internalization - -Interpolation
-What is the most appropriate definition of a scatterplot?
a A graph that uses dots to demonstrate relationships between two
categorical variables.
b A graph where lines are shown to represent positive or negative trends.
c A graph where the explanatory and response variables are plotted as
ordered pairs.
, d A graph where a positive causation is always represented with dots
forming a straight line. - -A graph where the explanatory and response
variables are plotted as ordered pairs.
-What does a strong positive correlation between two variables suggest?
a The explanatory variable is increasing and the response variable is
decreasing
b There is an association between the variables
c There is a causation between the variables
d Cannot determine - -There is an association between the variables
-{{ Scatterplot of distance from city center vs. rent. The linear equation for
this scatterplot is y equals negative one hundred five ten thousandths times
x plus ten and three hundred eighty one thousandths. }}
Using the scatterplot Distance from City Center vs. Monthly Rent, how far
can we expect an apartment to be from the city center if the monthly rent is
$ 980 ? Round your answer to the nearest mile.
a Around 54 miles
b Around 55 miles
c Around 56 miles
d Around 57 miles - -Around 55 miles
-Which correlation coefficient suggests the weakest correlation?
a −0.9
b −0.3
c 0.1
d 1 - -0.1
-What does it mean for a result or relationship to be statistically significant?
a The relationship is not caused by mere chance.
b The relationship is caused by chance.
c Your hypothesis test has failed.
d Your significance level is not high enough. - -The relationship is not caused
by mere chance.
-What is the process used to create the equation for the line of best fit?
a Completing the square
b Least squares estimation
c Fitting the line to the curve
d Linear approximation - -Least squares estimation
Regression Exam Questions and Answers
A researcher wants to know if there was a relationship between student age
and desire to complete a college degree. To answer this question, the
researcher used a local community college as the sampling frame and then
used stratified sampling to get a sample of students from 18 to 80 years old.
Based on the information given, is there any potential bias in this study?
a Yes, because the sampling frame does not match the intended population
of the question.
b Yes, because the sampling method will not give a representative sample.
c Yes, because a voluntary sample should have been used.
d No, there will likely be no bias in this study. - -Yes, because the sampling
frame does not match the intended population of the question.
-A researcher conducts an observational study and finds a correlation
between managers' income and the number of college credits earned. The
correlation coefficient was r=.85 with a regression equation of
y=515x+12000. What can you say about the relationship between these
variables?
a There is an association between these variables
b There is a causation between these variables.
c There is no relationship between these variables.
d There is not enough information to determine the relationship between the
variables. - -There is an association between these variables
-What technique is used to estimate the profit margin for a production level
of 25 thousand units, if a line of best fit is created to estimate profit margin
for production levels between 20 to 39 thousand units?
a Interpolation
b Linearization
c Extrapolation
d Internalization - -Interpolation
-What is the most appropriate definition of a scatterplot?
a A graph that uses dots to demonstrate relationships between two
categorical variables.
b A graph where lines are shown to represent positive or negative trends.
c A graph where the explanatory and response variables are plotted as
ordered pairs.
, d A graph where a positive causation is always represented with dots
forming a straight line. - -A graph where the explanatory and response
variables are plotted as ordered pairs.
-What does a strong positive correlation between two variables suggest?
a The explanatory variable is increasing and the response variable is
decreasing
b There is an association between the variables
c There is a causation between the variables
d Cannot determine - -There is an association between the variables
-{{ Scatterplot of distance from city center vs. rent. The linear equation for
this scatterplot is y equals negative one hundred five ten thousandths times
x plus ten and three hundred eighty one thousandths. }}
Using the scatterplot Distance from City Center vs. Monthly Rent, how far
can we expect an apartment to be from the city center if the monthly rent is
$ 980 ? Round your answer to the nearest mile.
a Around 54 miles
b Around 55 miles
c Around 56 miles
d Around 57 miles - -Around 55 miles
-Which correlation coefficient suggests the weakest correlation?
a −0.9
b −0.3
c 0.1
d 1 - -0.1
-What does it mean for a result or relationship to be statistically significant?
a The relationship is not caused by mere chance.
b The relationship is caused by chance.
c Your hypothesis test has failed.
d Your significance level is not high enough. - -The relationship is not caused
by mere chance.
-What is the process used to create the equation for the line of best fit?
a Completing the square
b Least squares estimation
c Fitting the line to the curve
d Linear approximation - -Least squares estimation
