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Question 9 The following data concerning income and educational attainment for s

ID: 1100663 • Letter: Q

Question

Question 9

The following data concerning income and educational attainment for several counties in Alabama were taken from the U.S. Census Website.

County

% High School Grads

Per Capita Income

Autauga

78.7

18,518

Chilton

66.2

15,303

Coosa

65.7

14,875

Dallas

70.3

13,638

Elmore

77.6

17,650

Jefferson

80.9

20,892

Lee

81.4

17,158

Lowndes

64.3

12,457

Macon

70.0

13,714

Montgomery

80.3

19,358

Pike

69.1

14,904

Shelby

86.8

27,176

Sum

891.3

205,643

Sum of Squares

66,818.87

3,705,400,931

?xy = 15,567,083.8

Find the least squares regression equation for predicting per capita income using the percentage of high school graduates.

y = 46.587 + 0.001616x

y = -9,577.8 + 518.662x

y = 4,634.9 + 358.472x

y = -18,096.5 + 474.365x

y = 12,781.2 + 753.291x

Question 10

Find the sample correlation coefficient between per capita income and percentage of high school graduates.

-0.8049

0.7664

-0.9116

0.8755

0.5922

Question 11

Find the value of the t statistic for testing H0: ?1 = 0 vs. HA: ?1 ? 0.

5.728

-2.929

9.400

-4.188

32.866

Question 12

Which of the following correctly describes the p-value for the test statistic in #11?

p-value < .01

.01 < p-value < .05

.05 < p-value < .10

.10 < p-value < .20

p-value > .20

Question 13

Considering #11-12 above, do the data provide significant evidence at the .05 level of a linear relationship between per capita income and the percentage of high school graduates?

yes

no

maybe

cannot be determined

six

Question 14

What is the expected change in per capita income associated with a 1% increase in the proportion of high school graduates?

about $474.36

about $1,273.41

about $226.19

about $1.62

about $358.47

County

% High School Grads

Per Capita Income

Autauga

78.7

18,518

Chilton

66.2

15,303

Coosa

65.7

14,875

Dallas

70.3

13,638

Elmore

77.6

17,650

Jefferson

80.9

20,892

Lee

81.4

17,158

Lowndes

64.3

12,457

Macon

70.0

13,714

Montgomery

80.3

19,358

Pike

69.1

14,904

Shelby

86.8

27,176

Sum

891.3

205,643

Sum of Squares

66,818.87

3,705,400,931

Explanation / Answer

Find the least squares regression equation for predicting per capita income using the percentage of high school graduates

c.y = 4,634.9 + 358.472x

10.Find the sample correlation coefficient between per capita income and percentage of high school graduates.

b.0.7664

11.Find the value of the t statistic for testing H0: ?1 = 0 vs. HA: ?1 ? 0.

a.5.728

12.Which of the following correctly describes the p-value for the test statistic in #11?

d.10 < p-value < .20

13.Considering #11-12 above, do the data provide significant evidence at the .05 level of a linear relationship between per capita income and the percentage of high school graduates?

a.yes

14.What is the expected change in per capita income associated with a 1% increase in the proportion of high school graduates?

e.about $358.47