All but one of the statements below contain a mistake.Which one could be true?
A)If the correlation between blood alcohol level and reaction time is 0.73, then the correlation between reaction time and blood alcohol level is -0.73.
B)The correlation between the breed of a dog and its weight is 0.435.
C)The correlation between gender and age is -0.171.
D)The correlation between height and weight is 0.568 inches per pound.
E)The correlation between weight and length of foot is 0.488.

Question

Quizplus · Accepted Answer

Correlation coefficients measure the strength and direction of a linear relationship between two variables on a scatterplot, ranging from -1 to 1. Choices A, B, C, and D are incorrect for the following reasons: A) Correlation is symmetric; the correlation from X to Y is the same as from Y to X, so if it's 0.73 in one direction, it's also 0.73 in the other, not -0.73. B) Correlation requires numerical variables, but breed is a categorical variable. C) Gender is a categorical variable, not numerical, so you can't compute a correlation coefficient with age directly. D) Correlation coefficients do not have units (like inches per pound); they are unitless. E) is plausible because it compares two numerical variables (weight and length of foot), which is appropriate for correlation analysis.

All but One of the Statements Below Contain a Mistake