HP (Hewlett-Packard) F2215AA#ABA Calculator User Manual


 
12-6 Statistical Operations
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 (s
x
) of the process:
Calculate the standard deviation of the times. (Treat all the data as x–values.)




Four data pairs
accumulated.
ÕÕ ()

Calculates the mean price
weighted for the quantity
purchased.
15.5 9.25 10.0
12.5 12.0 8.5
Keys: Display: Description:
 ()
Clears the statistics registers.

 Enters the first time.




Enters the remaining data; six
data points entered.
()



Calculates the standard deviation
time.