Answer :

We are given the function

[tex]$$
f(x)=\frac{1}{9}\cdot 3^x.
$$[/tex]

To find [tex]$f(5)$[/tex], substitute [tex]$x = 5$[/tex] into the function:

[tex]$$
f(5)=\frac{1}{9}\cdot 3^5.
$$[/tex]

Next, calculate [tex]$3^5$[/tex]. Since

[tex]$$
3^5 = 3\times 3\times 3\times 3\times 3 = 243,
$$[/tex]

we have

[tex]$$
f(5)=\frac{1}{9}\cdot 243.
$$[/tex]

Finally, compute the product:

[tex]$$
\frac{243}{9} = 27.
$$[/tex]

Thus, the value of [tex]$f(5)$[/tex] is [tex]$27$[/tex], which corresponds to option C.