I might get warned but say something nice for free points

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.

What is the 17th term in the arithmetic sequence in which a6 is 101 and a9 is 83

Idon't get undoing if its pass adding and subtracting so can someone ? x-2 over 5 = 18