Question

(14 points) College Graduation Rates. Data from the College Results Online website compared the 2011 graduation rate and median SAT score for 92 similar-sized public universities and colleges in the United States. The scatterplot below shows the relationship between these two variables along with the least squares fit. Round all calculated results to 4 decimal places. Graduation Rate by Median SAT 90 80 70 Graduation Rate TTTTTT 60 50 40 30 20 900 1000 1100 1200 1300 Median SAT 1. The relationship between median SAT score and graduation rate is positive strong 4, and linear . 2. The explanatory variable is median SAT and the response variable is graduation rate 4. The summary statistics for graduation rate and median SAT score are listed below. The correlation between graduation rate and median SAT score is 0.647. Median SAT score: mean = 1029.7, standard deviation = 80.4 Graduation rate: mean = 48.1, standard deviation = 13.9 3. The equation of the regression line is y =
(14 points) College Graduation Rates. Data from the College Results Online website compared the 2011 graduation rate and median SAT score for 92 similar-sized public universities and colleges in the United States. The scatterplot below shows the relationship between these two variables along with the least squares fit. Round all calculated results to 4 decimal places.

Answer 1

3)

	x̅ =		1029.7
	y̅ =		48.1
	sx=		90.4
	sy =		13.9
	r=		0.58
slope b1=r*sy/sx=			0.08918
intercept bo=y̅ +r(sy/sx)*(x̅)=			-43.730

y^ = -43.7301+0.0892x

4)

an incerase of 1 unit in ,,,,,,,increase of 0.0892 in

5)

predicted value =0.08918*1028-43.7301=

47.9484

6)

residual =48.4-47.9484 = -0.5484

lower than

7)

o A. No, because 1455 is beyond the range of the data used to build the regression model.