Question

Exponential Growth problem...see attached. I got r = .014384, but the answer key says otherwise.

Answer 1

i got a cartoon and some cars when clicking on the link

Answer 2

http://i40.tinypic.com/w0nqyb.jpg

Answer 3

How's that?

Answer 4

ok
what is "growth constant?" are you supposed to find k in
\[Ae^kt\]?

Answer 5

i meant
\[P(t)=A_0 e^{kt}\]

Answer 6

that's the formula that I used. I used 4.5 for A0

Answer 7

20 for time since 1980

Answer 8

6 on the other side

Answer 9

ok so you should be solving
\[6=4.5e^{20k}\] for k

Answer 10

yes

Answer 11

I divided both sides by 4.5, then took the natural log of both sides

Answer 12

I got .28768 = 20 k

Answer 13

\[\frac{6}{4.5}=e^{20k}\]
\[\frac{4}{3}=e^{20k}\]
\[20k=\ln(\frac{4}{3})\]
\[k=\frac{\ln(\frac{4}{3})}{20}\]

Answer 14

solving for k, I got .014384

Answer 15

Answer key says: .02310

Answer 16

\[k=0.0143841\] rounded

Answer 17

i get what you got

Answer 18

I don't know where they are getting this answer from in the key....must be a typo?

Answer 19

answer key is messed up

Answer 20

lol, thanks for checking with me

Answer 21

it happens. problems written my cadres of bored graduate students for extra cash, can easily be a mistake