Choose the correct answer

Question

If the points of a scatter plot all lie exactly along a straight line, then their correlation coefficient will be exactly equal to one.

Select one:

a. True

b. False

c. insufficient information

Answer 1

if the regression line is upward sloping then r=+1

if downward sloping r=-1

if flat, r=0

if the line is vertical, r is undefined, or 0/0

if all data falls on a line, r could be 1,-1 or 0 or undefined

you need more information to know which value of r

a is incorrect

b and c are correct

c is probably the best answer