Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

roblem 4.30 Dr. Lilian Fok, a New Orleans psychologist, specializes in treating

ID: 390990 • Letter: R

Question

roblem 4.30 Dr. Lilian Fok, a New Orleans psychologist, specializes in treating patients who are agoraphobic (i e, atraid to leave thieir homes). The following table indicates how many patients Dr. Fok has seen each year for the past 10 years. It also indicates what the robbery rate was in New Orleans during the same year 10 62 33 411 4 58 Number of Patients Robbery Rate per 1,000 Population 35 57 58.0 606 730 761 78.5 89.5 996 94.8 1032 1156 The simple linear regression equation that shows the best relationship between the number of patients and year is (round your responses to three decimal places where y- Dependent Variable and x Independent Variable.

Explanation / Answer

Solution:
Intercept can be calculated as
a = summation(y)*summation(x^2) - summation(x) summation(xy) / n*summation(x^2) - (summation(x))^2
a = 848.9*23595 - 475*42088.8 / 10*23595 - 475*475 = 3.643

X

Y

X2

Y2

XY

35

58

1225

3364

2030

33

60.6

1089

3672.36

1999.8

39

73

1521

5329

2847

41

76.1

1681

5791.21

3120.1

41

78.5

1681

6162.25

3218.5

54

89.5

2916

8010.25

4833

58

99.6

3364

9920.16

5776.8

55

94.8

3025

8987.04

5214

57

103.2

3249

10650.24

5882.4

62

115.6

3844

13363.36

7167.2

475

848.9

23595

75249.87

42088.8

Slope of the line can be calculated as
b =n*summation(XY) - summation(x) summation(y) / n*summation(x^2 ) - (summation(x))^2
b= 10*42088.8 - 475*848.9 / 10*23595 - 475*475 = 1.170

So linear regression line Y = 1.71046X + 3.64315

In year 11 no. of patients = 1.71046*11 + 3.64315 = 22.46
In year 12 no. of patients = 1.71046*12 + 3.64315 = 24.17
If coeffiecient of determination for linear regression model is 0.8640 which shows that show that 86.40% variablity in dependent variable explained by this model. So we can say that there is strong relationship between the no. of patients and year.



X

Y

X2

Y2

XY

35

58

1225

3364

2030

33

60.6

1089

3672.36

1999.8

39

73

1521

5329

2847

41

76.1

1681

5791.21

3120.1

41

78.5

1681

6162.25

3218.5

54

89.5

2916

8010.25

4833

58

99.6

3364

9920.16

5776.8

55

94.8

3025

8987.04

5214

57

103.2

3249

10650.24

5882.4

62

115.6

3844

13363.36

7167.2

475

848.9

23595

75249.87

42088.8