Respuesta :
(a)The population of the city after 30 years will be 463708.566 as per exponential growth.
(b) The value of the exponential 'r' is 4.5%.
What is the exponential growth of a system?
"Exponential growth is a process that increases quantity over time."
Here, f(x) = a(1 + r)ˣ
f(x) = exponential growth function
a = initial amount
r = growth rate
x = number of time intervals
(a)The population of the city is (A) = 256,000.
The rate of increase of population per year is (r) = 2% = 0.02.
Time period (n) = 30 years.
Therefore, the population after 30 years
= A(1 + r)ⁿ
= 256000(1 + 0.02)³⁰
= 463708.566
(b) Let, the total bacteria is x.
The rate of increase of bacteria per day is = r%
Time period (n) = 32 days.
Total increased in bacteria in 32 days = 309%.
After 32 days, the total number of bacteria is
= x + (x × 309/100)]
= x + 3.09x
= 4.09x
Therefore,
4.09x = [tex]x(1 + r)^{t}[/tex]
⇒ [tex](1 + r)^{32}[/tex] = 4.09
⇒ (1 + r ) = 1.045
⇒ r = 0.045
⇒ r = 4.5%
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