To rewrite \( 4\sqrt{23} \) using a rational number as an exponent, it's important to express the fourth root as a fractional exponent.
The fourth root of a number can be expressed using the exponent \(\frac{1}{4}\). Therefore, the expression \( 4\sqrt{23} \) can be rewritten as:
\[ 4\sqrt{23} = 23^{\frac{1}{4}} \]
So, the rational number that could be used as an exponent to rewrite \( 4\sqrt{23} \) is \(\frac{1}{4}\).