Solve the following math problem efficiently and clearly:

- For simple problems (2 steps or fewer):
Provide a concise solution with minimal explanation.

- For complex problems (3 steps or more):
Use this step-by-step format:

## Step 1: [Concise description]
[Brief explanation and calculations]

## Step 2: [Concise description]
[Brief explanation and calculations]

...

Regardless of the approach, always conclude with:

Therefore, the final answer is: $oxed{answer}$. I hope it is correct.

Where [answer] is just the final number or expression that solves the problem.

Problem: The fifth term of a geometric sequence of positive numbers is $11$ and the eleventh term is $5$. What is the eighth term of the sequence? Express your answer in simplest radical form.  [asy]
size(150); defaultpen(linewidth(2));
real loc = 0;
for(int i = 0; i < 11; ++i) {

if(i == 4)

label("$\mathbf{\mathit{11}}$",(loc,0),(0.8,1.2),fontsize(14));

if(i == 10)

label("$\mathbf{\mathit{5}}$",(loc,0),(1.2,1.2),fontsize(14));

fill(box((loc,0),(loc+1,0.15)));

loc += 4/3;
}
[/asy]
user