How to solve this with working out please

1. the following set of data represents the number of waiting times in minutes from a random sample of 30 customers waiting for service at a department store. 4 5 7 10 11 11 12 12 13 15 15 17 17 17 17 17 18 20 20 21 22 22 23 24 25 27 27 31 31 32 a. determine the number of classes and class interval.

Segment xz is bisected by point y. if xy = 12x, and the measure of xz = 18x – 6, solve for x

Which graph represents the solution set for the given system of inequalities? x+2y< 3 x+y> 4 3x-2y> 4