A Hotel Tracks the Number of Complaints Per Month

Multiple Choice

A hotel tracks the number of complaints per month. When the process is in control, there is an average of 35 complaints per month. Assume that a 2-sigma control limit is used. What is the upper control limit?

A) less than or equal to 35
B) more than 35 but less than or equal to 45
C) more than 45 but less than or equal to 55
D) more than 55