Dumplings -To-Go (DTG)provides Take-Out Dumplings and Noodle Dishes to Customers

Multiple Choice

Dumplings -To-Go (DTG) provides take-out dumplings and noodle dishes to customers at its chain of drive-through restaurants.The target for a customer's waiting time is 3.0 minutes +/- 1 minute.Each month,one of the managers observes the drive-through process and collects a sample of 4 waiting times a day over a 6 day period.The data from one restaurant appears below.If DTG were to construct an R-chart from this data,the 3-sigma UCL would be

A) 6.42
B) 5.87
C) 5.63
D) 5.01