After graduation, you accept a position as Purchasing Manager for Dockery Manufacturing (how exciting!). You are qualifying a source for leverage items and require a lead time between 18 and 23 days. After examining the suppliers bid information, you determine their current lead times are normally distributed and have a process mean of 21 days. If the target capability is 1.33, then what maximum standard deviation can the process have to be considered capable?

Group of answer choices

0.50

0.63

0.67

0.75

1.00