Median family income, y, was regressed against the proportion of the labour force who are high school graduates, x, using 1980 census data for 50 states. The results are:
y = 451463 + 22270x
r = 0.6347
(2651.56) (39.14)
a) What is the economic meaning of each of the estimated coefficients?
b) Test the hypothesis that median family income increases as the proportion of the labour force with high school education increases.
c) Also test the null hypothesis that this regression line passes through the origin.