What Must Be True for a Correlation Coefficient to Be

Question

What must be true for a correlation coefficient to be calculated between two traits?
A) The values for the traits must have been obtained from unbiased sampling.
B) The relationship between the two traits must be linear.
C) The traits must follow a normal distribution.
D) All of these choices are correct.

Accepted Answer

The correlation coefficient is a measure of the linear relationship between two variables. In order to calculate a correlation coefficient, the values for the traits must have been obtained from unbiased sampling, the relationship between the two traits must be linear, and the traits must follow a normal distribution.