A survey is designed by a professor to study the relationship between yearly income earned ($000) and years of higher education received. She determines the following model for her study:

YrInc = 10.6165 + 2.9098 YrEdu where YrInc is the yearly income, and YrEdu is the year of education.

a) A 95% prediction interval for a person with 8 years of education is between $22,110 and $43,820. Explain to the professor how she should interpret this interval.

b) A 95% confidence interval for the average yearly income for people with 8 years of education is between $30,970 and

$38,610. Explain to the professor how she should interpret this interval.

c) Now explain to her why these intervals are different.