A culture of bacteria has an initial population of 420 bacteria and doubles every 5 hours. Using the formula Pt - Po. 24, where P4 is the population after t hours, Po
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-by-step explanation:

what grade level is this? need to know so i can look in my old textbooks!

step-by-step explanation:

we have

using a graphing tool

see the attached figure

this is a quadratic equation (vertical parabola) open up

the vertex is a > vertex

the domain of the function is all real > interval (-∞,∞)

the range of the function is the > [-6.125,∞)

the function has two x->   and

the function is increasing over the > (0.25,∞)

the function is decreasing over the > (-∞,0.25)

the answer is d

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