[HP-12C] Angular coefficent from linear regression off by 1

[Dieter]

(05-06-2016 07:50 AM)Csaba Tizedes Wrote:  [ 6-step solution using r and s ]
BTW: the result is 11.09933164 and 0.1593408619. I don't know it is good for you or not...

In this particular case it's good enough of course, as this is the exact 10-digit result. ;-)

The method you suggested is short and elegant. However, it uses the regression coefficient and the two standard deviations, where all three are internally calculated using square roots. That's why this method is prone to slight errors in the last digit, just as the method suggested in the manual.

And that's why the suggested direct solution using the six registers is inherently more exact. As long as these data do not have too many significant digits (which usually is the case with empirical data) the results are exact. Even in the last digit. ;-)

So you can choose between a shorter and a potentially more exact solution.

Dieter