Which statement is not true about correlation matrices?
A) The diagonal elements all equal 0.
B) The upper triangular portion of the matrix is a mirror image of the lower triangular portion.
C) A correlation matrix indicates the coefficient of correlation between each pair of variables.
D) Usually only the lower portion of the matrix is considered.

Question

Quizplus · Accepted Answer

The diagonal elements of a correlation matrix always equal 1, not 0. This is because the correlation between a variable and itself is always perfect (i.e., r = 1). Therefore, the diagonal of the correlation matrix always shows the correlation between a variable and itself, which is always equal to 1.

Which Statement Is Not True About Correlation Matrices