MATH HELP PLS PLS I need help

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.

Find the equation of the trend line (line of best fit). show your work i'm using the points (34,76) (42,91)

Which expression is equivalent to -5(3x - 6/7)