Question

down options for Part (h) are: (d) or (b)

Complete parts (a) through (h) for the data below. 

x	20	30	40	50	60
y	79	75	70	62	50

 (b) Find the equation of the line containing the points (30,75) and (60,50).

 (c) Graph the line found in part (b) the scatter diagram. Choose the correct graph below. 

 (d) By hand, determine the least-squares regression line. 

 (e) Graph the least-squares regression line on the scatter diagram. 

 (f) Compute the sum of the squared residuals for the line found in part (b) 

 (g) Compute the sum of the squared residuals for the least-squares regression line found in part (d) 

 (h) Comment on the fit of the line found in part (b) versus the least-squares regression line found in part (d). 

The line in part _______  passes through the most points. The line in part _______ _______ the sum of the squared residuals, thus being the best-fitting line. ?

Drop 

Answer 1

f)

x	y	Predicted Y	Residuals	squared residuals
20	79	83.3	-4.3	18.8
30	75	75	0	0
40	70	66.7	3.3	11.1
50	62	58.3	3.7	13.4
60	50	50	0	0
Total				43.3

Sum of squared residuals=43.3

g)

x	y	Predicted Y	Residuals	squared residuals
20	79	81.4	-2.4	5.76
30	75	74.3	0.7	0.49
40	70	67.2	2.8	7.84
50	62	60.1	1.9	3.61
60	50	53	-3	9
Total				26.7

Sum of squared residuals=26.7

h) The line in part (d) passes through most of the points. The line in part (d) minimizes the sum of squared residuals, thus being the best fitting line.