Chapter 5 - Section 5.7 - Negative Exponents and Scientific Notation - Exercise Set - Page 409: 82

$72,400$

Since the exponent of $10^ 4 $ is $\text{ positive } 4 ,$ move the decimal point $ 4 $ places to the $\text{ right }.$ Hence, the given expression, $ 7.24\times10^4 ,$ is equivalent to \begin{array}{l}\require{cancel} 72,400 .\end{array}