Final answer:
The orbital period of an asteroid with a semi-major axis of 2.5 AU is approximately 3.95 years.
Step-by-step explanation:
The orbital period of an asteroid can be calculated using Kepler's third law, which states that the square of the orbital period is proportional to the cube of the semi-major axis of the orbit.
Given that the asteroid is orbiting at 2.5 AU, we can calculate its orbital period as follows:
Orbital period = sqrt(2.5^3) years = sqrt(15.625) years ≈ 3.95 years
Therefore, the orbital period of the asteroid would be approximately 3.95 years.