If the fourth term in the expansion of `(a x+1/x)^n \ is \ 5/2,\ ` then find the values of `a\ a n d\ n`.

Explanation

To solve the problem, we need to find the values of \( a \) and \( n \) given that the fourth term in the expansion of \( (ax + \frac{1}{x})^n \) is \( \frac{5}{2} \).

### Step-by-Step Solution:

1. **Identify the Fourth Term**:
The fourth term \( T_4 \) in the binomial expansion can be expressed using the formula:
\[
T_{r+1} = \binom{n}{r} (ax)^{n-r} \left(\frac{1}{x}\right)^r
...