Question

1. Assuming a linear relationship between X and Y, if the coefficient of correlation (r) equals −0.75, this means that:

	a.	there is very weak correlation.
	b.	the slope b1 is = −0.75.
	c.	the value of X is always greater than the value of Y.
	d.	None of these choices are true.

2. Which of the following is a property of the slope, b₁?

	a.	The slope equals one if X and Y have the same variance.
	b.	The slope has the same sign as r, the coefficient of correlation.
	c.	The slope equals one if r equals one.
	d.	All of these choices are true.

3. Consider the following data:

x	9	6	7	5	8
y	19	14	16	12	15

Calculate the covariance and the coefficient of correlation for the sample.

0.716

0.816

0.916

0.998

Answer 1