Question

The regression lines will be perpendicular to each other if the coefficient of correlation r is equal to.

• A. $1$ only
• B. $1$ or $-1$
• C. $-1$ only
• D. $0$

Answer 1

Answer: (B)

$1$ or $-1$

The two regression lines are perpendicular to each other.

When coefficient of correlation is perfectly positive or negative $r$ = The two regression lines coincide

Therefore the answer will be $1$ or $-1$