A teller at a drive-up window at a bank had the following service times (in minutes) for 20 randomly selected customers: What are the 3-sigma control limits? Select one: a. LCL = 4.385, UCL = 4.615 b. LCL 4.312, UCL = 4.689 c. LCL = 4.414, UCL = 4.586 d. LCL 4.212, UCL = 4.788 e. None of the other options. 1 SAMPLE 2 3 4 4.5 4.6 4.5 4.7 4.2 4.5 4.6 4.6 4.2 4.4 4.4 4.8 4.3 4.7 4.4 4.5 4.3 4.3 4.6 4.9