HP 20B manual 62

Statistical Operations

Table 10-1The Statistics Menu Items

Menu Item				Description
Nb Item				Number of items.
			Mean	Average of X values.
	X
		Mean		Average of Y values.
	Y
X Std. Dev				Standard deviation for X: a measure of how dispersed the x data values are
				about the mean.
Y Std. Dev				Standard deviation for Y: a measure of how dispersed the y data values are
				about the mean.
X Population Dev				Population Standard deviation for X: a measure of how dispersed the X data
				values are about the mean, assuming the data constitutes a complete set of
				data.
Y Population Dev				Population Standard deviation for Y: a measure of how dispersed the y data
				values are about the mean, assuming the data constitutes a complete set of
				data.
S.E.SamP.X				Sample error for X: a measure of how dispersed the X data values are about
				the mean sample standard deviation, assuming the data is a sampling of a
				larger, more complete data set.
S.E.SamP.Y				Sample error for Y: a measure of how dispersed the Y data values are about
				the mean sample standard deviation, assuming the data is a sampling of a
				larger, more complete data set.
Pred X				Predicts X for a given hypothetical value of Y, based upon the model calculated
				to fit the data.
Pred Y				Predicts Y for a given hypothetical value of X, based upon the model calculated
				to fit the data.
a				The a coefficient for the chosen regression model, which is the slope for a linear
				model.
b				The b coefficient for the chosen regression model, which is the y-intercept for a
				linear model.
Correlation				The correlation coefficient for the given (x, y) data. The correlation coefficient is
				a number in the range -1 through 1 that measures how closely the calculated
				line fits the data.
Covariance				A measure of how much two variables change in relation to one another.
Sigma X				The sum of the x values.

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