I have some stupid summer assignments and i need help (preferably right now!!!)

this is the only question i cant get right and its driving me crazy!

"The population P of a city is given by

P=145100e^(kt)

where t=0 represents 1970. In 1950, the population was 104200.
Find the value of k and use this value to predict the population in the year 2000

i got k=0.0165555515

and i got 238433.3236 for the answer

BUT its not correct... and thats where im going insane

[edit] alright i couldnt stand the suspense so i just submitted with the wrong answer

closed then

THere were some limits and derivatives questions that i was confused too but i figured those out

OK, so 1970 gives you t=0. So for 1950 t=-20 and for 2000 t=+30

In 1950 P=104200.
=> 104200=145100xe^(-20k)
=> 104200/145100 = e^-20k
=> ln (104200/145100) = -20k (where ln is the natural log)
=> [ln (104200/145100)]/(-20) = k
=> - (ln 0.7181)/20 = k
=> - (-0.3311)/20 = k
=> k = 0.0165555515

And that gives P=238433.3 for t=30

Well I get the same answer you do. I can't see an error anywhere in there, and to get the same answer for this we must have done the same thing. How do you know it's not right? Maybe the mark scheme or whatever has an error in it.

yea there was a mark scheme; you input it and itll tell you if you're right or wrong

i just gave up cause it was proly a bug, i tried doing it so many times im 100% it's right

thanks though

its over now, the due date was the 21st