A culture of bacteria has an initial population of 3900 bacteria and doubles every 2 hours. Using the formula $P_{t}=P_{0} \cdot 2^{\frac{t}{d}}$, where $P_{t}$ is the population after $t$ hours, $P_{0}$ is the initial population, $t$ is the time in hours and $d$ is the doubling time, what is the population of bacteria in the culture after 9 hours, to the nearest whole number?

Step 1 ：We are given a culture of bacteria with an initial population of 3900 bacteria that doubles every 2 hours. We are asked to find the population of the bacteria after 9 hours.

Step 2 ：We can use the formula for exponential growth, \(P_{t}=P_{0} \cdot 2^{\frac{t}{d}}\), where \(P_{t}\) is the population after \(t\) hours, \(P_{0}\) is the initial population, \(t\) is the time in hours and \(d\) is the doubling time.

Step 3 ：Substituting the given values into the formula, we get \(P_{t}=3900 \cdot 2^{\frac{9}{2}}\).

Step 4 ：Solving the equation, we find that \(P_{t} = 88247\).

Step 5 ：Thus, the population of bacteria in the culture after 9 hours, to the nearest whole number, is \(\boxed{88247}\).