Respuesta :

Answer:

f(4) = 82.944

Step-by-step explanation:

f(x)=a(b)^x

a is the initial value and b is 1 + growth rate in decimal form

a = 40 and

b = 1 +.2 = 1.2

f(x) = 40 (1.2)^x

f(4) means let x =4

f(4) = 40 (1.2)^4

f(4) = 82.944