Question

commute time
how many students take less than 40 minutes to get to school?

Explanation:

Step1: Identify relevant intervals

We need to consider intervals 0 - 9, 10 - 19, 20 - 29, 30 - 39.

Step2: Sum up frequencies

The frequencies for 0 - 9 is 4, for 10 - 19 is 6, for 20 - 29 is 2, for 30 - 39 is 1. So the sum is $4 + 6+2 + 1$.
$4+6 + 2+1=13$

Answer:

13