Suppose that k independently selected samples are available, each one consisting of n observations on a normally distributed variable. Denote the sample standard deviations by $s _ { 1 } , s _ { 2 } , \ldots , s _ { k}$ The values $s _ { 1 } , s _ { 2 } , \ldots \ldots , s _ {k }$ are plotted in sequence on an S chart. The center line of the chart will be at height equals to the
A) average of the values $s _ { 1 } , s _ { 2 } , \ldots \ldots , s _ { k }$
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B) range of the values $s _ { 1 } , s _ { 2 } , \ldots \ldots , s _ { k }$
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C) standard deviation of the values $s _ { 1 } , s _ { 2 } , \ldots \ldots , s _ { k }$
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D) first quartile of the values $s _ { 1 } , s _ { 2 } , \ldots \ldots , s _ { k }$
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E) third quartile of the values $s _ { 1 } , s _ { 2 } , \ldots \ldots , s _ { k }$
)

Question

Quizplus · Accepted Answer

The center line of an S chart, which is used for monitoring the variability of a process, is typically set at the average of the sample standard deviations ($s _ { 1 } , s _ { 2 } , \ldots , s _ { k}$). This provides a baseline from which to assess variations in process variability.

Suppose That K Independently Selected Samples Are Available, Each One s1,s2,…,sks _ { 1 } , s _ { 2 } , \ldots , s _ { k}s1​,s2​,…,sk​

Suppose That K Independently Selected Samples Are Available, Each One $s _ { 1 } , s _ { 2 } , \ldots , s _ { k}$