Question

Which of the following correlation coefficients would correspond to a strong linear relationship in a data set? a. 0 b. 7 c. 0.9 d. 0.4

Answer 1

Answer: c) 0.9

The correlation coefficient r is always between -1 and 1, inclusive of both endpoints. We can write
`-1 \le r \le 1`

If r = 0, then we have no linear correlation at all. If r = 1, then we have perfect positive correlation. If r = -1, then we have perfect negative correlation.

We see that r = 0.9 is close to r = 1, so we have strong positive linear correlation going on here.