One-Variable Statistical Calculations - HP -22S Owner's Manual

The STAT Menu and Statistical Functions (Continued)
Menu Key Description
{;;:,y}
Displays menu for means:
{;;:}
Arithmetic mean (average) of the x-values.
{Y} Arithmetic mean (average) of the y-values.
{;;:w} Weighted mean of the x-values weighted according to the
y-values.
{s} Displays menu for sample standard deviation:'
{s:><:} Standard deviation of the x-values.
{sy}
Standard deviation of the y-values.
{loR. } Displays menu for linear regression and linear estimation:
{x} Estimate of x for a given value of y.
{Y}
Estimate of y for a given value of x.
{r} Correlation coefficient.
t
{m}
Slope of the calculated line.
{b} v-intercept of the calculated line.
• The standard deviation is a measure of how dispersed the numbers are about the mean.
The HP-22S calculates the sample standard deviation, which assumes the data is a sam-
pling of a larger, complete set of data. If the data constitutes the entire population of data,
the true population, see page 64, ·Calculating the Population Standard Deviation."
t
The correlation coefficient is a number in the range -1 through
+
1 that measures how
closely the data fits the calculated line. A value of
+
1 indicates a perfect positive correla-
tion, -1 indicates a perfect negative correlation. A value close to 0 indicates the curve is a
poor fit.
One-Variable Statistical Calculations
If you enter a list of single numbers, they are stored as
x-values.
You
can then calculate:
• Mean and standard deviation of
x
(x and
sx) .
• Summations:
n, };x,
and
};x
2 .
5: Statistical Calculations 63