Calculating logaritm

RuddyFox

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Joined
Mar 20, 2019
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Hi,

I need to calculate a bodymass for a fossil mammal from it's lower molar row lenght (LMRL). The equation is straightforward enough but it seems that I must be misunderstanding something as I'm getting the wrong result.

Values:

BM = bodymass (in grams)
LMRL = 106.1 mm
Slope = 3.03
Intercept = -0.39

The equation is thus:

Log BM = 3,03*log(LMRL) -0.39

I'm getting the answer 321,093 since this should come out in grams that would mean 32 kg which I know is much too small a number for this mammal. What am I understanding wrong? I'm guessing it has something to do with "Log BM" and that it requires some extra step to acquire the actual bodysize?

I would be very thankful for any help!

RF
 
I'm getting 560 kg. (I am assuming the 3,03 is supposed to be 3.03? And I am using log base 10.) I don't know the size of the animal you are interested in but 560 kg isn't too far off for a small to mid-size animal.

Can you print out some intermediary calculator steps? I can't figure out how to replicate your results.

-Dan

Addendum: If you are using log base e I get around 930 kg.
 
Please show us your work so we can see what is not correct. That will be the quickest way for you to receive help.
 
That sounds like a very likely estimate! But how did you arrive at that?

What I did was I calculated 3.03 * log (106.1) - 0.39

I'm doing this using a calculator, typing in exactly the values above. I get the answer = 5.74791761322 (actually this is a completely different answer than I got before I must have made a mistake then as well)

I suppose I don't really understand what log BM stands for in this case, does it mean that I get the answer as a log of the bodymass?

Sorry, this is probably really basic math and I'm just totally rusty.
 
Gosh, I think I figured it out.

If I take 10^5.75 =562341.325... and then I have to change that into kg so that gives me 562.34 am I doing it right now?
 
Thanks a lot for all of your help! It helped me get my squirrel brained thoughts straight. ?
 
Like topsquark, I get an answer very close to 560 kg. Unlike topsquark, I object to having animals that large in the house.
 
Yeah, I sort of forgot to multiply by g there.

But if it's a kitty! (Hey, Garfield was pretty fat.) Maybe it's a prehistoric kitty.

Hmmmm.... That would mean I have to get a prehistotic sized bag of kitty litter....

-Dan
 
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