Question

The number of bacteria N in a culture is modeled by N=200e^kt

where t is the time in hours. If N=360 when t=3 what is the time required for the original population to quadruple in size?

Answer 1

use the given values for N and t to find constant k. i guess initial population is 200, then quadruple would be 4x200=800, so plug in N=800 and the k that you found, into equation and solve for t.

Answer 2

How do u find K that is my main problem I have 360=200e^3k

Answer 3

take the natural log to isolate k, ln(360/200)=3k, ==> k=ln(360/200)/3

Answer 4

once you have k, solve for t by taking the natural log again, when N is quadrupled. My guess you're learning about logs?

Answer 5

Its a review for my final and I am having trouble remembering anything past 4 chapters ago and we have done 9 so Im struggling

Answer 6

is there any way to write this problem out without a log? My scientific calculator app is malfunctioning?

Answer 7

you can't get a numerical answer without taking the ln, easiest way is to use an actual scientific calculator, i guess phones wouldn't be allowed on exam anyway, if that's what you're using