Correlation Practice

Being correlated means that two things are

• related

• causing each other

• unrelated

We wish to investigate whether a person’s age can be predicted from their IQ score. Which is the explanatory variable (EV)?

• Age

• IQ Score

• Both Age and IQ Score

• None of the Above

Describe the association between the number of lanes rented and the number of people bowling.

• Non-linear association

• Negative linear association

• No association

• Positive linear association

What COULD be the approximate value of the correlation coefficient for the scatter plot?

• -.851

• -.162

• 0.211

• 0.905

Data is analyzed comparing hours studied and grades. It is determined that the correlation coefficient is 0.92. What does this mean?

• There is a strong positive correlation between studying and grades.

• There is a strong negative correlation between studying and grades.

• There is a weak positive correlation between studying and grades.

• There is a weak negative correlation between studying and grades.

Correlation or Causation: the number of bus stops increases, the number of car sales decreases?

• Correlation

• Causation

Describe the correlation coefficient if

r = 0.90

• Positive, weak

• Positive, strong

• Negative, weak

• Negative, strong

Estimate the correlation coefficient.

• r is close to 1

• r is close to -1

• r is close to 0

• r is close to -0.5

• r is close to 0.5

Estimate the correlation coefficient

• r = 1

• r = -1

• r ≈ -0.8

• r ≈ 0.8

• r ≈ -0.5

What does a positive correlation on a scatterplot indicate?

• As one variable increases, the other variable tends to decrease.

• There is no relationship between the two variables.

• As one variable decreases, the other variable tends to increase.

• As one variable increases, the other variable also tends to increase.