maths --plse help me..

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A bacteria culture has an initial population of 600. After 4 hours the population has grown to 1200. Assuming the culture grows at a rate proportional to the size of the population, find the function representing the population size after t hours and determine the size of the population after 8 hours.

  • maths --plse help me.. -

    Use
    amount = a e^(kt) where a is the initial value, k is a constant, and t is in hours

    1200 = 600 e^(k(4)
    2 = e^(4k)
    4k = ln 2
    k = ln2 /4

    amount = 600 e^((ln2/4)t)

    when t=8
    amount = 600 e^(2ln2)
    = 2400

    well, duh
    Since the doubling period seems to be 4 hours
    in 8 hours they would have doubled twice
    600 --> 1200 --> 2400

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