Answer:
b) .474
Explanation:
If 62% go to a four-year college, that means that those who don't represent 38% of the high-school graduates.
You pick up someone who is NOT going to a four-year college (so, he's among the 38%)... what's the chance he's in the 18% of the whole high-school graduates population that found a job?
To calculate that probability, we have to divide 18% by 38%.
P = 18% / 38% = 0.4736, so 0.474
Since we are sure he doesn't go to a four-year college, there's 47.4% of chances he finds a job.