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Algebra Problem Help Needed - mlwilliamsiv - 02-16-2010
Hey Guys...
I've been racking my brain trying to figure this problem out:
The number of bacteria in a certain population increases according to an exponential growth model, with a growth rate of 4% per hour. How many hours does it take for the size of the sample to double? Round your answer to two decimal places.
I've been searching on google for some formulas to help me but I just can't seem to get it... I figure since the problem doesn't tell me how many bacteria there are then I could just pick a number like 100. I'm just not good with formulas and word problems.
Any help would be greatly appreciated thanks...
From a loyal degree seeker,
Algebra Problem Help Needed - NAP - 02-16-2010
Hi!
Have you seen these sites?
Rate of growth equation help? - Yahoo! Answers
Exponential Growth and Decay
They look promising.
I hope this helps!
Algebra Problem Help Needed - mlwilliamsiv - 02-16-2010
Thanks NAP
Algebra Problem Help Needed - ideafx - 02-16-2010
I believe the answer is 17.33 hours, but please double check my work.
The formula you want is A = Pe^rt
There's more information about it here: Exponential Word Problems
A = Pe^rt
2 = e^.04t
ln(2) = .04t*ln(e)
0.693 = .04t
17.33 = t