Complete the Numerical Expression: 7.3 = ?

To solve this problem, we'll follow these steps:

• Step 1: Identify the decimal and its components.
• Step 2: Convert the decimal part to a fraction.
• Step 3: Combine the whole number and fraction into a mixed number.

Now, let's work through each step:
Step 1: The given decimal is $7.3$. This can be separated into the whole number $7$ and the decimal fraction $.3$.
Step 2: To convert $.3$ into a fraction, we observe that it represents three tenths, which is $\frac{3}{10}$.
Step 3: Combine the whole number and the fractional part to form a mixed number. Thus, $7.3$ becomes $7\frac{3}{10}$ as a mixed number.

Therefore, the solution to the problem is $7\frac{3}{10}$.