
Section 6: Functions continue103




The illustration below shows what happens in the stack when you execute
MEAN of SDEV . The
contents of the stack registers are changed...


...from this...

...to this.




t




z

Y

MEAN
of y or
SDEV of y

MEAN
of x or
SDEV of x





LAST

x



Deleting and Correcting Data


If you key in an incorrect value and have not executed
Σ+ , press
CLX or
to delete the incorrect
number or digits, and key in the correct number.


If one of the values is changed, or if you discover that one of the values
is in error after you have executed the Σ+
function, you can correct the summations by using the
Σ– (summation minus) function
as follows:



1.

Key in the incorrect data pair into the X and Yregisters.



2.

Press g
Σ– to delete the incorrect data.



3.

Key in the correct values for x and y. (If one value of an x, y data pair
is incorrect, both values must be deleted and reentered.)



4.

Press Σ+ .



The corrected values for mean and standard deviation are now obtainable by
executing the MEAN and
SDEV functions.
