In: Statistics and Probability
6. A social scientist would like to analyze the relationship between educational attainment (in years of higher education) and annual salary (in $1,000s). He collects data on 20 individuals. A portion of the data is as follows:
Salary | Education | ||||
35 | 1 | ||||
67 | 6 | ||||
⋮ | ⋮ | ||||
32 | 0 | ||||
a. Find the sample regression equation for the model: Salary = β0 + β1Education + ε. (Round answers to 2 decimal places.)
Salaryˆ=Salary^= Not attempted+ Not attempted Education
c. What is the predicted salary for an individual who completed 5 years of higher education? (Round coefficient estimates to at least 4 decimal places and final answer to the nearest whole number.)
SalaryˆSalary^ $
Salary |
Education |
35 |
1 |
67 |
6 |
79 |
2 |
46 |
1 |
69 |
7 |
78 |
5 |
111 |
6 |
62 |
0 |
20 |
4 |
25 |
5 |
100 |
6 |
47 |
5 |
64 |
3 |
66 |
9 |
154 |
7 |
61 |
0 |
87 |
1 |
60 |
3 |
123 |
7 |
32 |
0 |
Education (X) | Salary (Y) | X * Y | |||
1 | 35 | 35 | 1 | 1225 | |
6 | 67 | 402 | 36 | 4489 | |
2 | 79 | 158 | 4 | 6241 | |
1 | 46 | 46 | 1 | 2116 | |
7 | 69 | 483 | 49 | 4761 | |
5 | 78 | 390 | 25 | 6084 | |
6 | 111 | 666 | 36 | 12321 | |
0 | 62 | 0 | 0 | 3844 | |
4 | 20 | 80 | 16 | 400 | |
5 | 25 | 125 | 25 | 625 | |
6 | 100 | 600 | 36 | 10000 | |
5 | 47 | 235 | 25 | 2209 | |
3 | 64 | 192 | 9 | 4096 | |
9 | 66 | 594 | 81 | 4356 | |
7 | 154 | 1078 | 49 | 23716 | |
0 | 61 | 0 | 0 | 3721 | |
1 | 87 | 87 | 1 | 7569 | |
3 | 60 | 180 | 9 | 3600 | |
7 | 123 | 861 | 49 | 15129 | |
0 | 32 | 0 | 0 | 1024 | |
Total | 78 | 1386 | 6212 | 452 | 117526 |
Equation of regression line is
b = 5.46
a =( \Sigma Y - ( b * \Sigma X) ) / n
a =( 1386 - ( 5.4574 * 78 ) ) / 20
a = 48.02
Equation of regression line becomes
When X = 5
= 48.016 +
5.457 X
= 48.016 +
5.457 * 5
=
75.3 75