Alexa transports flowers for Rolling Rosie's Garden Center. On her last route, she earned $450.80. If Alexa earned $0.40 for every mile, how far did she drive?

Let "x" be the number of miles Alexa drove.

Alexa earned $0.40 * x = $0.40x for driving x miles.
We know that $0.40x = $450.80.
Dividing both sides by $0.40, we get x = $450.80 / $0.40 = 1127 miles.
Alexa drove 1127 miles. Answer: \boxed{1127}.