1. The problem statement, all variables and given/known data A company allows a maximum failure rate of 1 out of 250,000 parts. To insure this quality goal, failed parts must be how many standard deviations from the mean? Use Excel to solve. 2. Relevant equations z= (X-μ)/σ 3. The attempt at a solution Hi! So I'm assuming that this is a normal distribution. I'm a little confused, I kind of feel like there wasn't enough information provided to find how many standard deviations need to be away from the mean. So far I've tried finding the z-value using excel and assuming that 1/250000 is my alpha value: =NORM.S.INV(1/250000) = -4.46518 I was thinking about trying to plug it into this formula to find σ: z= (X-μ)/σ Am I on the right track with this? I wasn't given an X or a μ, so I don't know how I would go about solving this.