Question

Please help me.. I'm so confused on this :(..

A culture started with 2,000 bacteria. After 2 hours, it grew to 2,400 bacteria. Predict how many bacteria will be present after 10 hours. Round your answer to the nearest whole number.

Note: When solving for k, round to four decimal places.

P = ae^k^t

@hartnn

Answer 1

The equation looks like this:

\[\LARGE P = Ae^{kt}\]

Answer 2

@kelliegirl33

Answer 3

DO u have to use that equation?...its obvios it increases by 200 each hour.

Answer 4

Yes, I have to use that equation =/.

Answer 5

well that stinks...can't help u sorry...
@hartnn

Answer 6

\(P\) is the amount of bacteria right?
\(t\) is time.
You'd know what e is by calculator.

Answer 7

@Dakotafox79

Answer 8

No I don't know how to figure out e via calculator ._. this is confusing me :(.. Sorry I suck at Algebra v.v.. @AnImEfReaK

Answer 9

wanna do it the quick way?

Answer 10

If there is a quick way... Then sure why not lol..

Answer 11

lets forget \( P = Ae^{kt}\) and use only the numbers given to you

Answer 12

you start with \(2000\) and two hours later you have \(2400\) meaning every two hours in increases by a factor of \(\frac{2400}{2000}=1.2\)
since you started with \(2000\) you can model this as
\[\large P=2000(1.2)^{\frac{t}{2}}\]

Answer 13

Why is it just showing "\.[\large P=2000(1.2)^{\frac{t}{2}}.\]" to me??

Answer 14

you notice i only used the numbers you were given, no logs or anything like that
we can do it that way to if you like, it is the same, just takes longer
now you want the population at 10 hours
put
\[\large P=2000(1.2)^{\frac{10}{2}}=2000(1.2)^5\] and use a calculator to get the answer

Answer 15

refresh your browser

Answer 16

you are not seeing the latex code for some reason, if you fresh your browser you should see it
let me know

Answer 17

Still shows the same thing ._.

Answer 18

P = 2000(1.2)^(t/2) is the formula you can use

Answer 19

then at t = 10 you get
P = 2000(1.2)^(10/2)= 2000 (1.2)^5
then use a calculator to find it

Answer 20

Never mind, I see it now.. Using Google Chrome instead of IE sorry.

Answer 21

yeah, i.e. is a total waste
delete it

Answer 22

On a school PC can't lol.

Answer 23

oh ok

Answer 24

@loser of course it works with \(P(2)\) you get
\[P(2)=2000\times (1.2)^1=24000\] that is how we got it to begin with

Answer 25

@Dakotafox79 you good from there? now you need a calculator, but that is all

Answer 26

How do I do a fraction as a power? How would I input that onto a calculator?

Answer 27

you don't need a fraction as a power
the \(\frac{10}{2}=5\)

Answer 28

Ohhhh okay. So I just multiply 2,400 to the 5th power correct?

Answer 29

here lets use this
http://www.wolframalpha.com/input/?i=2000%281.2%29^5

Answer 30

Oh okay I see.

Answer 31

oh hold on, you are a bit confused still i think
formula is
\[\large P=2000\times(1.2)^{\frac{t}{2}}\]

Answer 32

4976.64 is the answer correct?

Answer 33

\[P(10)=2000\times (1.2)^{\frac{10}{2}}=2000\times (1.2)^5\] exponent first, multiplication last

Answer 34

yes, but it says round to the nearest whole number

Answer 35

It says round to the nearest whole number which would be 4977.

Answer 36

4977

Answer 37

@Loser66 when you find \(k\) you do some rounding
that is why it is not exact

Answer 38

So that's all it is @satellite73 4977? :O

Answer 39

yes
we can do it the other way if you like

Answer 40

Nope, that way works for me xD. Much easier.. God you're a hero! A life saver! xD Good job dude! :D Thanks so much :)

Answer 41

but notice again that i used only the numbers given to you
you were given 2000 , 2400 , 2 and from that alone we got the equation

Answer 42

yw

Answer 43

yw