A culture contains 1700 bacteria initially and doubles every 30 minutes. Find a function that models the number of bacteria n(t) after t minutes. (Enter the growth rate using natural logarithm).
$\displaystyle n = 1700 \cdot 2^{kt}$
$\displaystyle 3400 = 1700 \cdot 2^{30k}$
solve for $\displaystyle k$ and you have your function.
or ...
$\displaystyle n = 1700 \cdot e^{kt}$
$\displaystyle 3400 = 1700 \cdot e^{30k}$
solve for $\displaystyle k$ ... same drill.