MATH 225N WEEK 8 ASSIGNMENT DATA
ASSOCIATION EVALUATION STUDY GUIDE
2026 VERIFIED ANSWERS
◉ predicted variable Answer: The ___________ variable is the variable
whose value can be explained by the value of the explanatory
variable
◉ scatter plot Answer: A ___________________ is a graph that shows the
relation between two quantitative variables.
◉ When the explanatory variable increases so does the predicted
variable. The correlation coefficient is close to +1 Answer: What
does it mean to say two variables are positively associated?
◉ When the explanatory variable increases, the predicted variable
decreases. The correlation coefficient is close to -1. Answer: What
does it mean to say two variables are negatively associated.
◉ +1 Answer: What value r gives a perfect positive linear relation.
◉ -1 Answer: What value r gives a perfect negative linear relation
, ◉ False
No, they could have a nonlinear relation and still have a coefficient
close to 0. Answer: True or False
If the linear correlation coefficient is close to 0 then the two
variables have no relation
◉ Correlation indicates the the two numbers are related in some
way.
Causation requires more proof that there is no lurking variable that
creates the relationship. Answer: What is the difference between
correlation and causation
◉ The matrix in the calculator or excel that automatically calculates
the correlation coefficient. Answer: correlation matrix
◉ A variable that is not included as an explanatory/response
variable in the analysis but can affect the relationships between
variables. Answer: lurking variable
◉ mix up (something) with something else so that the individual
elements become difficult to distinguish. Answer: confound
ASSOCIATION EVALUATION STUDY GUIDE
2026 VERIFIED ANSWERS
◉ predicted variable Answer: The ___________ variable is the variable
whose value can be explained by the value of the explanatory
variable
◉ scatter plot Answer: A ___________________ is a graph that shows the
relation between two quantitative variables.
◉ When the explanatory variable increases so does the predicted
variable. The correlation coefficient is close to +1 Answer: What
does it mean to say two variables are positively associated?
◉ When the explanatory variable increases, the predicted variable
decreases. The correlation coefficient is close to -1. Answer: What
does it mean to say two variables are negatively associated.
◉ +1 Answer: What value r gives a perfect positive linear relation.
◉ -1 Answer: What value r gives a perfect negative linear relation
, ◉ False
No, they could have a nonlinear relation and still have a coefficient
close to 0. Answer: True or False
If the linear correlation coefficient is close to 0 then the two
variables have no relation
◉ Correlation indicates the the two numbers are related in some
way.
Causation requires more proof that there is no lurking variable that
creates the relationship. Answer: What is the difference between
correlation and causation
◉ The matrix in the calculator or excel that automatically calculates
the correlation coefficient. Answer: correlation matrix
◉ A variable that is not included as an explanatory/response
variable in the analysis but can affect the relationships between
variables. Answer: lurking variable
◉ mix up (something) with something else so that the individual
elements become difficult to distinguish. Answer: confound
