To find the original price \( P \) of the shirt, we can set up the equation based on the information given.
We know that the sale price of the shirt ($7.98) is half of the original price \( P \). This can be represented by the equation:
\[ \frac{P}{2} = 7.98 \]
To solve for \( P \), we can multiply both sides of the equation by 2 to isolate \( P \):
\[ P = 7.98 \times 2 \]
Now, let's calculate:
\[ P = 15.96 \]
Thus, the original price \( P \) of the shirt is:
\[ P = 15.96 \text{ dollars} \]