Answer
The y-intercept of the givne equation is $38957$.
$\\\\$This means that the average annual income of an American woman in the year 2005 was $\$38,957$.
Work Step by Step
The y-intercept can be found by setting x=0.
$\\\\$Doing this gives:
$\\\\y=4207.4x+38957
\\\\y=4207.4(0)+38957
\\\\y=0+38957
\\\\y=38957$
$\\\\$Thus, the y-intercept of the given equation is $38957$.