Statistics aplet 10-15
Two-variable
Plotting You can plot:
• histograms ( )
• box-and-whisker plots ( )
• scatter plots ( ).
Once you have entered your data ( ), defined your 
data set ( ), and defined your Fit model for two-
variable statistics (
SETUP-SYMB), you can plot your 
data. You can plot up to five scatter or box-and-whisker 
plots at a time. You can plot only one histogram at a time.
Statistic Definition 
MEANX Mean of x- (independent) values.
ΣX Sum of x-values.
ΣX2 Sum of x
2
-values.
MEANY Mean of y- (dependent) values.
ΣY Sum of y-values.
ΣY2 Sum of y
2
-values.
ΣXY Sum of each xy.
SCOV Sample covariance of independent 
and dependent data columns.
PCOV Population covariance of 
independent and dependent data 
columns
CORR Correlation coefficient of the 
independent and dependent data 
columns for a linear fit only 
(regardless of the Fit chosen). 
Returns a value from 0 to 1, where 
1 is the best fit.
RELERR The relative error for the selected 
fit. Provides a measure of accuracy 
for the fit.
HP 39gs English.book  Page 15  Wednesday, December 7, 2005  11:24 PM