Exp 16 pre and post-lab sig fig.

[robert zellmer]

I've received a few questions about the sig. fig. in exp 16 when it comes
to averaging the f.p. determinations to get the average f.p. which you 
report
on your sheet and in the on-line data-entry post-lab.

In 1210 you discussed how you can average several numbers and gain sig. 
fig.
That is correct.  However, in practice when dealing with experimental data
including an additional sig. fig. really can't safely be done with only 
2 or 3
numbers.  If you think about exp 1 in which you were plotting your data
if you had only 2 pts the line would have gone through both points and
wouldn't have shown any effect of random errors.  Adding one more point
wouldn't make it much better.

When you add up your determinations for the f.p. for each trial adding only
three values isn't enough to give confidence in reporting an extra s.f.  
If you
did five determinations and averaged those I would say you could probably
report 1 extra s.f.

I thought this had been addressed in the "Directions" button in the on-line
data input program.  I guess it wasn't for the pre-lab.  Keep this in mind
for the post-lab input.

Dr. Zellmer