A culture of bacteria has an initial population of 350 bacteria and doubles every 6 hours. Using the formula P, start subscript, t, end subscript, equals, P, start subscript, 0, end subscript, dot, 2, start superscript, start fraction, t, divided by, d, end fraction, end superscriptP t =P 0
⋅2
d
t
​

, where P, start subscript, t, end subscriptP
t
​
is the population after t hours, P, start subscript, 0, end subscriptP
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?