Answer
$\frac{12}{35}$
Work Step by Step
We know that $probability=\frac{\text{number of favourable outcomes}}{\text{number of all outcomes}}$
The total number of students (the number of all outcomes) is $350$
By using the table, there are $98$ from private colleges and $22$ from high income public colleges, thus there are $98+22=120$ "good outcomes".
Hence the probability here is: $\frac{120}{350}=\frac{12}{35}$