Question

We have learned that 99.73% of the parts from a process in control will fall within 6 standard deviations of the mean or average (3 above the mean and 3 below the mean). this particular width, 6 standard deviations, is called the natural tolerance. data from a screw machine indicates a process mean = .39483 and a standard deviation = .00011. what is the natural tolerance of this process?

Answer 1

The data from a screw machine have process mean =0.39483 and standard deviation=0.00011

The natural tolerance of data is nothing but the width 3 standard deviation below mean and 3 standard deviation above mean.

It is given as

Lower limit = μ - (3 * σ ) and upper limit = μ + (3 * σ )

We have μ=0.39483 and σ = 0.00011

So the natural tolerance level is

Lower limit = 0.39483 - (3 * 0.00011) = 0.3945

Upper limit = 0.39483 + (3 * 0.00011) = 0.39516

The natural tolerance of the process with mean 0.39483 and standard deviation 0.00011 is (0.3945, 0.39516)