When dating samples by radioactive techniques, age dates commonly have errors associated with them. These errors are expressed as a plus or minus followed by a number at the end of the age date. For example, the Vishnu Schist has been dated to be 1.702 billion years +/- 4 million years. What is the total error associated with this date? Express both as the total number of years and as a percentage of the total age. Given age of the rock, is this a significant degree of error?

( Hint: 1.702 billion = 1.702 million). Maybe you will understand that hint, because I sure don’t.