What is a least squares regression line? What does regression tell us?

2. Why is it dangerous to extrapolate outside the experimental region?

3. Given the following

Book	Pages (x variable)	Price (y variable)
A	525	$7.50
B	615	$8.15
C	550	$7.95
D	685	$9.50
E	525	$7.55
F	600	$8.00
G	487	$6.95

a. Create a scatter diagram which shows the trendline (this is the regression line) and provides the coefficient of determination?

b. What is the equation of the trendline from the graph?

c. According to the equation of the trendline from your graph, if a book had 617 pages, how much should it cost?

d. According to the equation of the trendline from your graph, if a book costs $9.62, how many pages should it have?

4. You are presented with four values for Pearson's product moment correlation coefficient ( r ). Which one shows the strongest relationship? Why?

a. 0

b. 0.19

c. 0.59

d. -0.99