5.) We hypothetically observe that the higher ones education, the happier one is. We hypothesize that this is actually because of income: people with higher education tend to make higher incomes, and it is these higher incomes, not education, that causes the higher happiness. Here are hypothetical models (using a dependent variable where at all happy, up to happy):

Independent Variable Model 1 Model 2

Education (in years) 0.35*** ???

Income (in thousands of dollars) --- 0.03***

Constant 0.50 -2.50

R-Squared 0.10 0.15

n 1000 1000

To support the hypothesis, what is the most likely number that would go in the place of the ??? in Model 2?

a.) .03

b.) .20**

c.) .35*

d.) .50***