Estimate the process standard deviation.
-A company that manufactures health food snacks produces low sodium rice chips. To
Monitor the process for sodium levels, chips are selected periodically and the amount of
Sodium (mg) measured. For each of thirty samples consisting of 8 chips, the mean and
Range in sodium content is determined. The average of the means across all samples is 55
Mg and the average range is 2.2 mg. The estimated process standard deviation (σˆ ) is
A) 0.773 mg.
B) 2.683 mg.
C) 0.073 mg.
D) 16.176 mg.
E) 1.833 mg.

Question

Quizplus · Accepted Answer

The process standard deviation can be estimated using the formula: σˆ = R̅ / d2, where R̅ is the average range and d2 is a constant that depends on the sample size. For a sample size of 8, d2 = 2.326. Therefore, σˆ = 2.2 mg / 2.326 = 0.773 mg.

Estimate the Process Standard Deviation