It changes daily. As at 4-Feb, 1 Mexican Peso is worth $0.08. 1 US Dollar is worth 13 Pesos.
As of 4/25/09 1 Mexican peso = 0.0749850 US dollars. The inverse of that is 1 US dollar = 13.3360 Mexican pesos. You can get a rate any time on a currency site like XE.com.
As of this moment I am answering this question the rate of US Dollar to Chilean Peso is 1=489.25.
1 USD = 578.3 Chile Peso Note: Value as of 13 Feb 2009
100 pesos = 7.6 American dollars