HP10B / HP10BII error on regression  example Message #1 Posted by Gene on 6 Apr 2002, 3:40 p.m.
The HP10B and HP10BII give an incorrect answer for the yintercept on certain regression problems.
Excel and the TIBAII Plus give the correct answer.
Example:
X Y
2400 1000
3700 1350
2500 1250
3000 1800
2500 1200
3100 1700
3000 1150
This is a managerial accounting problem. X stands for units produced while Y is for mixed overhead.
Anyway, the HP10B and HP10BII give the equation
Y = 510.375 + 0.29166667 X
But Excel and the BAII Plus give
Y = 508.3333 + 0.291666667X
The Y intercept on the 10B is wrong.
Any ideas why? Internal roundoff?
I remember problems similar to this on old HPs where people would try to find the mean and std deviation on 999999997 and 9999999995 and 9999999996 and it would zonk out because of hte large numbers involved, but these numbers are not large enough that this should be a problem.
?
Gene
