After a special medicine is introduced into a petri dish containing a bacterial culture, the number of bacteria remaining in the dish decreases rapidly. The number of bacteria decays by a factor of \dfrac{1}{15} 15
1

start fraction, 1, divided by, 15, end fraction every 6.76.76, point, 7 minutes, and can be modeled by a function, N, which depends on the amount of time, t (in minutes).
Before the medicine was introduced, there were 90{,}00090,00090, comma, 000 bacteria in the Petri dish.
Write a function that models the number of bacteria t minutes since the medicine was introduced.