Valhalla Legends Forums Archive | Yoni's Math Forum | Simple math expressions...

AuthorMessageTime
Mephisto
For some reason I keep getting different answers with different online calculators I'm using, so I just want a definitive answer from a TI-83 (or something similar) calculator which I would use if I had...

(4.131e-5) / (9.58e-4 * 3.58e-4) = ?
(6.579e-5) / (9.34e-4 * 5.34e-4) = ?
(9.486e-5) / (9.05e-4 * 7.05e-4) = ?
(1.097e-4) / (8.90e-4 * 8.90e-4) = ?

If you're curious, I'm calculating equilibrium constants from my lab.  The most ideal results of these calculations would for these to all be the same (they're the concentrations of all the ions in equilibrium of the 4 different equilibrium systems setup).
April 20, 2006, 3:22 AM
kamakazie
Trying to fit data to match what it should theoretically be is really bad science (and should get you in trouble, IMO). The results for each individual equation should be the same among several calculators to the appropriate amount of significant digits (which looks like 3, but I can't be too sure without seeing your lab). I would suggest just marking them down as they are calculated. You can use google to get the values.
April 20, 2006, 3:48 AM
Mephisto
I'm not trying to match data to what it should be... I simple want the answer to these expressions...sheesh.  The online calculators don't yield the same results as Ti calculators (floating point precision) and thus I really need a Ti calculator for these which have higher precision with floating points.
April 20, 2006, 3:53 AM
kamakazie
[quote author=Mephisto link=topic=14807.msg150883#msg150883 date=1145505194]
I'm not trying to match data to what it should be... I simple want the answer to these expressions...sheesh.  The online calculators don't yield the same results as Ti calculators (floating point precision) and thus I really need a Ti calculator for these which have higher precision with floating points.
[/quote]

Well then...straight form my TI-83:
[code]
(4.131e-5) / (9.58e-4 * 3.58e-4) = -.3689279949
(6.579e-5) / (9.34e-4 * 5.34e-4) = -.3513024166
(9.486e-5) / (9.05e-4 * 7.05e-4) = -.3708069833
(1.097e-4) / (8.90e-4 * 8.90e-4) = .013294199
[/code]
April 20, 2006, 5:29 AM
Mephisto
I believe I wrote the expressions wrong.  I meant for the 'e' to be scientific notation, which I believe is a cap 'E.'  ~sorry

But I got the answers I needed, thx anyways:)
April 20, 2006, 6:09 AM

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