What is the possible minimum sigma value (given $1\sigma$, $2\sigma$, $3\sigma$, $4\sigma$, $5\sigma$, $6\sigma$) one can use when we want a less than 0.3% defect ratio?
My approach was to implement $68-95-99.7$ rule, and get $3\sigma$ as a correct answer. Would it be right method, or there are missing parts?
My answer would be to choose $3\sigma$ from the Z-table, but unsure whether it gives correct values for this problem
@StubbornAtom Regarding previous comment, does that question have an answer to this problem? I suppose there was not an exact answer to that.