I was trying to solve the following question but I keep getting the wrong answer, could anyone help me out and see why?
A bacteria culture starts with 900 bacteria and grows at a rate proportional to its size. After 4 hours there will be 3600 bacteria. How long will it take for the population to reach 1150 ?
I found the equation to represent this problem as: $900*e^{.347t}$.
I then set this equation equal to 1150: $900*e^{.347t} = 1150$. I end up with the expression: $ln(1.27778) = .347t$ which when I solve I get 0.7064, which is giving me the wrong answer in my homework. Did I miss a step I have to take?