## College Algebra (6th Edition)

$\frac{6}{7}$
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 $140$ low income and $160$ middle income families, thus there are $140+160=300$ non-high income families. Hence the probability here is: $\frac{300}{350}=\frac{6}{7}$