Explanation:

- Let's denote the three positive numbers as $a$, $b$, and $c$.

- When the average of any two is added to the third, we get:

1. $\frac{a+b}{2}+c=154$

2. $\frac{b+c}{2}+a=148$

3. $\frac{c+a}{2}+b=132$

- Solving these equations:

- Equation 1: $a+b+2c=308$

- Equation 2: $b+c+2a=296$

- Equation 3: $c+a+2b=264$

- Adding these equations: $4a+4b+4c=868$. Simplifying gives $a+b+c=217$.

- Option 4: 217 is the correct answer.