Uranium, an important component of both nuclear weapons and nuclear reactors, has two major isotopes—U-238, which has a half-life of approximately 4.5 billion years, and U-235, which has a half-life of approximately 700 million years. Both were present in equal amounts at the time of the creation of the Earth, 4.5 billion years ago. How many billion years after the creation of the Earth had the amount of radiation from uranium decayed to half the amount present at the time of the creation of the Earth? (Round your answer to the nearest hundredth of a billion years.)

Uranium, an important component of both nuclear weapons and nuclear reactors, has two major isotopes—U-238, which has a half-life of approximately 4.5 billion years, and U-235, which has a half-life of approximately 700 million years. Both were present in equal amounts at the time of the creation of the Earth, 4.5 billion years ago. How many billion years after the creation of the Earth had the amount of radiation from uranium decayed to half the amount present at the time of the creation of the Earth? (Round your answer to the nearest hundredth of a billion years.)