C784 Module 6: Correlation &
Regression Exam with Complete
Solutions
lurking variable - ANS-A variable that is not included in an analysis but that is related to
two (or more) other associated variables which were analyzed.
simple linear regression - ANS-the prediction of one response variable's value from one
explanatory variable's value
Simpson's Paradox - ANS-A counterintuitive situation in which a trend in different
groups of data disappears or reverses when the groups are combined.
degree - ANS-The largest exponent in a mathematical expression or equation.
causation - ANS-A relationship of cause and effect between two or more variables.
linear interpolation - ANS-Estimation using the linear regression equation is between
known data points.
association - ANS-A pattern or relationship between two variables.
coordinate plane - ANS-A tool for graphing consisting of a horizontal x-axis and a
vertical y-axis.
regression equation - ANS-An equation used to model the relationship between two
quantitative dependent and independent variables.
scatterplot - ANS-A graph that uses dots on a coordinate plane to show the relationship
between variables.
Regression Analysis - ANS-a statistical tool that quantifies the relationship betwn a
response variable and one or more explanatory variables
least squares - ANS-A technique for finding the regression line.
slope-intercept form - ANS-A common format for the equation of a line: y = mx + b,
where m is the slope and b is the y-intercept.
, regression line - ANS-The line of best fit to show the relationship between variables, the
one that minimizes distance from each data point to the line.
A linear regression equation takes the following form:
y = mx^2 + b. True or False? - ANS-false.
This is not the form that a linear regression equation takes.
Linear regression is always of degree 1, so the exponent of 2 associated with the x
makes this a non-linear equation.
A linear regression "best-fit-line" can be estimated using least squares. True or False? -
ANS-true.
Least squares estimation is the most common technique used to estimate the best-fit-
line in linear regression.
Linear extrapolation is always a reliable method of prediction. True or False? - ANS-
false.
Extrapolation assumes that the linear pattern of the data will continue outside of the
range of data points. This may not always be the case and therefore may not always be
a reliable method of prediction.
Linear interpolation is a technique used to make a prediction that falls between known
data points. True or False? - ANS-true.
Linear interpolation is a technique used to make a prediction that falls between known
data points, using the linear regression equation.
Least squares estimation is a technique for predicting future data values. True or False?
- ANS-false. Least squares estimation is a technique used to estimate the best-fit-line in
linear regression.
In linear regression, least squares estimation is commonly used to find the line-of-best-
fit?
CORRELATION - ANS-A linear relationship between two variables. This relationship
can be either positive or negative.
A correlation describes whether two variables have a linear relationship with one
another.
POSITIVE CORRELATION - ANS-indicates that two variables' values move in the same
direction as one another. If two variables have a positive correlation, when one variable
Regression Exam with Complete
Solutions
lurking variable - ANS-A variable that is not included in an analysis but that is related to
two (or more) other associated variables which were analyzed.
simple linear regression - ANS-the prediction of one response variable's value from one
explanatory variable's value
Simpson's Paradox - ANS-A counterintuitive situation in which a trend in different
groups of data disappears or reverses when the groups are combined.
degree - ANS-The largest exponent in a mathematical expression or equation.
causation - ANS-A relationship of cause and effect between two or more variables.
linear interpolation - ANS-Estimation using the linear regression equation is between
known data points.
association - ANS-A pattern or relationship between two variables.
coordinate plane - ANS-A tool for graphing consisting of a horizontal x-axis and a
vertical y-axis.
regression equation - ANS-An equation used to model the relationship between two
quantitative dependent and independent variables.
scatterplot - ANS-A graph that uses dots on a coordinate plane to show the relationship
between variables.
Regression Analysis - ANS-a statistical tool that quantifies the relationship betwn a
response variable and one or more explanatory variables
least squares - ANS-A technique for finding the regression line.
slope-intercept form - ANS-A common format for the equation of a line: y = mx + b,
where m is the slope and b is the y-intercept.
, regression line - ANS-The line of best fit to show the relationship between variables, the
one that minimizes distance from each data point to the line.
A linear regression equation takes the following form:
y = mx^2 + b. True or False? - ANS-false.
This is not the form that a linear regression equation takes.
Linear regression is always of degree 1, so the exponent of 2 associated with the x
makes this a non-linear equation.
A linear regression "best-fit-line" can be estimated using least squares. True or False? -
ANS-true.
Least squares estimation is the most common technique used to estimate the best-fit-
line in linear regression.
Linear extrapolation is always a reliable method of prediction. True or False? - ANS-
false.
Extrapolation assumes that the linear pattern of the data will continue outside of the
range of data points. This may not always be the case and therefore may not always be
a reliable method of prediction.
Linear interpolation is a technique used to make a prediction that falls between known
data points. True or False? - ANS-true.
Linear interpolation is a technique used to make a prediction that falls between known
data points, using the linear regression equation.
Least squares estimation is a technique for predicting future data values. True or False?
- ANS-false. Least squares estimation is a technique used to estimate the best-fit-line in
linear regression.
In linear regression, least squares estimation is commonly used to find the line-of-best-
fit?
CORRELATION - ANS-A linear relationship between two variables. This relationship
can be either positive or negative.
A correlation describes whether two variables have a linear relationship with one
another.
POSITIVE CORRELATION - ANS-indicates that two variables' values move in the same
direction as one another. If two variables have a positive correlation, when one variable
