To simplify the expression \((4^{2.3})^7\), we can use the property of exponents \((a^m)^n = a^{m \cdot n}\). Applying this property, we get:
\[ (4^{2.3})^7 = 4^{2.3 \cdot 7} \]
Now, we can calculate \(2.3 \cdot 7\):
\[ 2.3 \cdot 7 = 16.1 \]
Thus, we have:
\[ (4^{2.3})^7 = 4^{16.1} \]
So, the expression equivalent to \((4^{2.3})^7\) is:
\[ 4^{16.1} \]