To find the original price \( p \) of the shirt, we know that the sale price of $7.98 is half of the original price. We can express this relationship with the equation:
\[ \frac{p}{2} = 7.98 \]
Now, to solve for \( p \), we can multiply both sides of the equation by 2:
\[ p = 7.98 \times 2 \]
Calculating that gives:
\[ p = 15.96 \]
Thus, the original price of the shirt is \( p = 15.96 \) dollars.