A culture of bacteria has an initial population of 450 bacteria and doubles every 4 hours. Using the formula Pₜ = P₀ ⋅ 2ᵗ/ᵈ, where Pₜ is the population after t hours, P₀​ 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 3 hours, to the nearest whole number?