1. The following regression results relate to a study of the salaries of public school teachers in a midwestern city:
|
Variable
|
Coefficient
|
Standard Error
|
t-ratio
|
|
Constant
|
20,720
|
6,820
|
3.04
|
|
EXP
|
805
|
258
|
|
|
|
|
|
|
R-squared = 0.684; n = 105
|
|
|
|
Standard error of the estimate = 2,000
|
|
|
EXP is the experience of teachers in years of a full-time teaching
|
a. What is the t-ratio for EXP? Does it indidcate that experience is a statistically significant determinant of salary if a 95 percent confidence level is desired?
b. What percentage of the variation in salary is explaned by this model?
c. Determine the point estimate of salary for a teacher with 20 years of experience.
d. What is the approximate 95 percent confidence interval for your point estimate from part (c)?