A researcher estimates that a fossil is 3200 years old. Using carbon-14 dating, a procedure used to determine the age of an object, the researcher discovers that the fossil is 3600 years old. a. Find the percent error.
-11.1%
-12.5%
-88.8
-112.5%

b. What other estimate gives the same percent error?
___ years old

Explain your reasoning.