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ÕÕ(  )

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  

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Four data pairs accumulated.Calculates the mean price weighted for the quantity purchased.
Sample Standard Deviation

Sample standard deviation is a measure of how dispersed the data values are about the mean sample standard deviation assumes the data is a sampling of a larger, complete set of data, and is calculated using n – 1 as a divisor.

Press () for the standard deviation of x–values.Press Õ() for the standard deviation of y–values.

The (σ) and (σ) items in this menu are described in the next section, "Population Standard Deviation."

Example: Sample Standard Deviation.

Using the same process–times as in the above "mean" example, May Kitt now wants to determine the standard deviation time (sx) of the process:

15.5

9.25

10.0

12.5

12.0

8.5

Calculate the standard deviation of the times. (Treat all the data as x–values.)

Keys:

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

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()

Display:Description:

Clears the statistics registers. Enters the first time.Enters the remaining data; six data points entered.

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 Calculates the standard deviation time. 