A researcher calculates the correlation coefficient between two variables and finds $r = 0.68$. After examining the residual plot, the researcher notices a clear curved pattern. What does this imply about the use of the correlation coefficient in this context?
Question 2
Which of the following is the correct formula for the sample correlation coefficient $r$ between two variables $X$ and $Y$?
Question 3
A set of paired data has a correlation coefficient $r = 0.8$. If each $X$ value is multiplied by 2 and each $Y$ value is multiplied by 3, what will be the new correlation coefficient?
Question 4
Which of the following best describes the effect of adding a strong nonlinear pattern (such as a quadratic relationship) to a dataset that originally had a linear relationship with a correlation coefficient $r = 0.9$?
Question 5
Suppose a study finds a correlation coefficient $r = 0.85$ between the number of hours spent exercising per week and the resting heart rate. After controlling for age, the partial correlation coefficient is found to be $r = 0.40$. What does this suggest?
Correlation Quiz — High School Probability And Statistics | A-Warded
