Answer:
b. 0.63
Explanation:
Given that:
The Purchasing Manager for Dockery Manufacturing is qualifying a source for leverage items and require a lead time between 18 and 23 days.
We can say that the Lower specification limit LSL = 18 and Higher specification limit USL = 23
Mean = 21
The target capability is 1.33
The objective is to determine the maximum standard deviation can the process have to be considered capable
From above ;
The process capability can be determined by the formula:
[tex]Process Capability = \dfrac{(USL -LSL)}{(6*standard \ deviation)}[/tex]
[tex]Process \ Capability = \dfrac{(23 -18)}{(6*standard \ deviation)}[/tex]
The process capability requires to be minimum (1.33) in order to be capable;
Thus;
[tex]1.33 = \dfrac{(23 -18)}{(6*standard \ deviation)}[/tex]
[tex]1.33 = \dfrac{(5)}{(6*standard \ deviation)}[/tex]
standard deviation = [tex]\dfrac{(5)}{(6*1.33)}[/tex]
standard deviation = 0.6265
standard deviation = 0.63