A critical dimension in your manufacturing process has been specified as being 2.5" +/- 0.06". The process is known to be in control and to have a process mean of 2.5". What is the maximum standard deviation the process can exhibit if it must operate at "six sigma level" (i.e., no more than 3.4 million defects per million opportunities)?

Round your final answer (not the intermediate calculations) to four decimal places.