what is the correct answer

A process in a mobile phone manufacturing project has an upper control limit of 0.12. What is the standard deviation of the process if the upper control limit is set at 3 Sigma?

  1. 0.5

  2. 0.4

  3. 0.12

  4. 0.36

Correct answer is B. I don't understand how they calculated?

3 Sigma = 0.12, therefore, the Sigma or the standard deviation = 0.4 

 

It shd be .04 not .4 right?

Can somebody explain?

 

Thanks Pawarji