Is there a relationship between the raises administrators at Country University receive and their performance on the job?

A faculty group wants to determine whether job rating (x) is a useful linear predictor of raise (y). Consequently, the group considered the linear regression model:

E(y)=β₀+β₁x

The faculty group obtained the following prediction equation:

? = 14,000 - 2,000x

Which of the following statements about the model E(y) = β₀+β₁x is correct?

a) The model hypothesizes that the raises for the administrators fall in a perfect straight line.

b) The model hypothesizes that, on average, administrators make more money than professors.

c) The model hypothesizes that knowing an administrator's rating (x) will determine exactly the administrator's raise (y).

d) The model hypothesizes a line of means; as rating (x) increases, the mean raise E(y) moves up or down along a straight line.