Increasing inventory exposes variability in production processes

Cycle counting is an inventory-control method whereby storeroom personnel physically count a small percent of the total number of items each day

Indicate whether the statement is true or false

The upper and lower specifications for a service are 10 min. and 8 min., respectively. The process average is 9 min. and the process capability ratio is 1.33. What is the process standard deviation?

A) 0.1 B) 0.15 C) 0.20 D) 0.25