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reaĺly really quick question :D (2 Viewers)

DepressedPenguino

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Q: how many years will it take for the population of kangaroos to double?

Say i worked out that it takes approximately 18.0196 years for a population of kangaroos to double, do i express my answer as 18 years or 19 years?
 

InteGrand

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(Out of curiosity) What would we have done if the calculated value had come out as 18.0000000001?
 

Squar3root

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(Out of curiosity) What would we have done if the calculated value had come out as 18.0000000001?
imo, we would not be able to get to that many sig, fig. accuracy so I would round my answer down to 18 but in general I learnt that you just round up because when you round down, you may not meet the constraint of the question but when you round it up, you do.

I don't think you'll lose too many marks for rounding down if your process and working is correct, just depends on the marker
 

VBN2470

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Lol, then you would probably just leave it at 18 then, can't be too fussy about it.
 

Speed6

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But the real question is, what if kangaroos didn't exist?

We must go deeper....
 

BLIT2014

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I'd put rounded to 19 years.
 
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PhysicsMaths

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In this case, the kangaroo is 7 days away from being born. So the question is... do you get no kangaroo at all, or a prematurely born kangaroo?
 

braintic

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Why would you turn 18.02 into 19. It's not asking for an integer number of years .... the kind of question people are getting confused with would say something like "What is the minimum number of complete years for the population to double?". And if you did do this, why on earth would anyone call it 'rounding' ?

And .... why does anyone believe that the exponential growth model could possibly be used for a population of only 17 bacteria? The model is based on the fact that individual randomness is averaged out over large populations, and its use is completely meaningless in such small populations.
 

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