Answer
The y-intercept of $75$ means that in 2008, there were $75,000$ people who were employed as physician assistants in the United States.
Work Step by Step
The given equation has $x$=number of years after 2008 and $y$ = number of people, in thousands, employed as physician assistants in the United States after 2008
$\\\\$From Part A of this item, the y-intercept was found to be $75$.
$\\\\$This means that in 2008, there were $75,000$ people employed as physician assistants in the United States.