Answer
$\frac{50}{87}$
Work Step by Step
We know that $probability=\frac{\text{number of favourable outcomes}}{\text{number of all outcomes}}$
The total population (the number of all outcomes) is $174$
By using the table, the total number of people who completed 4 years of high school or some college, here is $56+44=100$
Hence the probability here is: $\frac{100}{174}=\frac{50}{87}$