#### Answer

$\frac{28}{87}$

#### Work Step by Step

P(E) = $\frac{no.\ of\ outcomes\ in\ favor}{Total\ no.\ of\ outcomes}$
We use the data in the table from the textbook to find the probability of a given education level. A total of 174 million people were included in the US Census Bureau study.
E: Had four years of high school only
Favorable outcomes= {56}
P(E) = $\frac{56}{174}$ = $\frac{28}{87}$