A department store wants to test if its four cashiers serve, on average the same number of customers per hour. The following table gives the results for the number of customers served per hour during observations.

Cashier 1: 12, 13, 12, 15, 19, 17

Cashier 2: 15, 14, 16, 13, 13

Cashier 3: 14, 21, 16, 14, 18, 13

Cashier 4: 22, 14, 21, 19, 18

Determine the treatment variation.

Multiple Choice:

a) 65.6576

b) 50.5463

c) 212.1545

d) 230.1111