Titan has a radius of 2500.0 km and a mean density of 2.2 g/cm3. Earth's Moon has a radius of 1737.0 km and a mean density of 3.4 g/cm3. What is the ratio of gravitational acceleration on Titan compared to that on the Moon? The gravitational constant is G = 6.67 × 10-11 m3 kg-1 s-2.