Respuesta :
the tale-tell fellow is the base of the exponent ˣ.
if that number is less than 1, is a decay factor, if it's more than 1, is growth.
1.09 is cleary more than 1, so is growth, at what rate?
[tex]\bf \qquad \textit{Amount for Exponential Growth} \\\\ A=P(1 + r)^t\qquad \begin{cases} A=\textit{accumulated amount}\\ P=\textit{initial amount}\dotfill &P\\ r=rate\to r\%\to \frac{r}{100}\dotfill &0.0r\\ t=\textit{elapsed time}\dotfill &t\\ \end{cases} \\\\\\ f(x)=4.7(1.09)^x\implies f(x)=4.7(1+\stackrel{\stackrel{r}{\downarrow }}{0.09})^x \\\\\\ r=0.09\implies \stackrel{\textit{converting it to percentage}}{r=0.09\cdot 100}\implies r=\stackrel{\%}{9}[/tex]
Exponential functions are mostly used to represent growth of population.
The true option is: (d) Exponential growth function; 9%
The function is given as:
[tex]\mathbf{f(x) = 4.7 \cdot 1.09^x}[/tex]
An exponential function is represented as:
[tex]\mathbf{f(x) = a \cdot b^x}[/tex]
By comparison:
[tex]\mathbf{b = 1.09}[/tex]
When b is greater than 1, then the function is a growth function.
Next, we calculate the constant percentage rate of growth (r)
If b is greater than 1, then:
[tex]\mathbf{b = 1 + r}[/tex]
Substitute 1.09 for b
[tex]\mathbf{1 + r = 1.09}[/tex]
Subtract 1 from both sides
[tex]\mathbf{r = 0.09}[/tex]
Express as percentage
[tex]\mathbf{r = 0.09 \times 100\%}[/tex]
[tex]\mathbf{r = 9\%}[/tex]
Hence, the growth rate is 9%
Hence, the true option is: (d) Exponential growth function; 9%
Read more about exponential growth and decay functions at:
https://brainly.com/question/14355665