For this case we have a function of the form:
Where,
A: initial population of bacteria
b: growth rate
x: number of hours
Since the diameter is double every hour, then:
We must now look for the value of A.
To do this, we evaluate an ordered pair of the graph:
For (1, 2):
Clearing A we have:
Then, the function is given by:
For after 9 hours we have:
Answer:
the diameter of the bacteria after 9 hours is: