Answer
$\frac{10}{21}$
Work Step by Step
We know that $probability=\frac{\text{number of favourable outcomes}}{\text{number of all outcomes}}$
The total number of students who went to public college (the number of all outcomes) is $252$
By using the table, out of the $252$ students, there are $120$ who qualify for the low income bracket, thus there are $120$ "good outcomes".
Hence the probability here is: $\frac{120}{252}=\frac{10}{21}$
