Answer:
The missing value is 128
Explanation:
we know that
The equation of the exponential function is of the form

where
a is the initial value (value of the function when the value of x is equal to zero)
b is the base
r is the rate
b=(1+r)
In this problem , looking at the table, we have that the number of bacteria is doubled every second
so

substitute in the formula

where
f(x) is the number of bacteria
x is the time in seconds
For x=4 sec
substitute

