SOLUTION: A model for the number of people N in a college community who have heard a rumor is given by the equation:N=P(1-e^(-0.15d)) where P is the total population of the community and d i

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: A model for the number of people N in a college community who have heard a rumor is given by the equation:N=P(1-e^(-0.15d)) where P is the total population of the community and d i      Log On


   



Question 598213: A model for the number of people N in a college community who have heard a rumor is given by the equation:N=P(1-e^(-0.15d)) where P is the total population of the community and d is the number of days elapsed since the rumor began. If the number of students is 1,000 find the number of days when 500 students would have heard the rumor.
I have
450=1000(1-e^(-0.15d))
450/1000=1-e^(-0.15d)
9/2=1-e^(-0.15d)
7/2=-e^(-0.15d)
divide by -1
-7/2=e^(-0.15d)
-0.15d=ln(-7/2)
and I'm stuck because of the -7/2, it doesn't work...need help!

Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


Why did you substitute 450 for N when the problem wants to know how long it takes N to get to 500? Secondly, since when does ? More like , wouldn't you say?

Take it from here:



which is to say:



Good luck and let me know how it comes out.

John

My calculator said it, I believe it, that settles it
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