In: Statistics and Probability
A grinding machine in an auto-parts factory prepares axles with a target diameter of μ = 40.33 millimeters (mm). The machine has some variability, so the standard deviation of the diameters is σ = 0.006 millimeter. The machine operator inspects a random sample of 9 axles each hour for quality-control purposes and records the sample mean diameter x .
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Please help!
Solution :
Given that ,
mean = = 40.33
standard deviation = = 0.006
n = 9
sample distribution of sample mean is ,
=
= 40.33
sampling distribution of standard deviation
= / n = 0.006 / 9
= 0.002