All of this assumes that you're using the calculator's statistics matrix

of course.

Try the Owner's Manual, Chapter 28 "Programming Examples", "Summary

Statistics" pages 262-269. The programs listed there should get you the

sum of squares and sum of products values.

For the sum of a column, just use the TOT command to get a vector

containing the sum of each column, and the GET command to extract the

value for whichever column you're interested in. It should be rather

trivial to write a program that uses SumPAR (where Sum represents upper

case Greek sigma) to determine which column is x and which one y.

Also see "Median of Statistics Data" pages 270-275.

Check out anything in the Owner's Manual or Reference Manual that has

anything to do with either statistics or arrays.

Of course, using summary statistics methods, there's a greater

likelihood that information will be lost due to rounding off, especially

in the sum of squares and sum of products. Back in the days when we did

this on paper or with calculators that used summary statistics methods,

we used what we referred to as "encoded data". Instead of using the

actual data, we used the difference from some set value (typically, but

not always, the most significant digits that were the same for all of

the data), multiplied by whatever power of 10 gave us whole numbers to

work with.

For example, if the input data were 12.3453, 12.3404, and 12.3429, then

the algorithm for obtaining the encoded value could be to subtract 12.34

and then multiply that result by 10000, giving us 53, 4, and 29 to work

with. After computing our statistical results, we would decode them

back; in the above example, we might find the mean of the encoded data

to be (approximately) 29 which we divided by 10000 and then added to

12.34 to obtain the result of 12.3429.

Even for calculators that keep all of the data in a matrix, I often find

it easier to enter the data in "encoded" form (it's easy enough to do

the encoding in my head), and then multiply a column by a power of 10

and add a constant to the column. This saves a lot of repetitive

keystrokes.

Regards,

James