A culture of bacteria has an initial population of 640 bacteria and doubles every 2 hours. Using the formula P_t = P_0\cdot 2^{\frac{t}{d}}P t =P 0
⋅2 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 7 hours, to the nearest whole number?