Please help me with question 4. Specifically, I need help with parts B & C. Please check that my answers are correct. Thanks!

Question 4: a) If the mass of one object goes up, the gravitational force goes up(proportionally or inversely?(circle correct answer) b) If the moon were twice as massive as and it is THE SAME size, how would that change the gravitational pull on the Earth? _If the moon is twice as massive, the gravitational pull on Earth would double, but the forces on both would be proportional (the two objects involved in gravitational forces always experience the SAME force). c) If the moon were twice as massive as it is (it is about 1.2 to 2% the mass of the Earth), how would that change the gravitational pull on the Earth? The gravitational pull would be times (larger or smaller. (COMPARING the MOON to EARTH: The moon's mean radius is 1,079.6 miles, the earth is 3,959 miles. Put another way, The diameter of the Moon is 3,474 km. Now, let us compare this to the Earth. The diameter of the Earth is 12,742 km. This means that the Moon is approximately 27% the size of the Earth.) Informational link: http://www.space.com/18135-how-big-is-the-moon.html (Information on size of the earth & moon) The mass of the Moon is 7.347 x 1022 kg. But the Earth is much more massive. The mass of the Earth is 5.97x 1024 kg. This means that the mass of the Moon is only 1.2% of the mass of the Earth. NOTE: Gravity on the moon is 1/6 earth's. Read more: http://www.universetoday.com/20489/moon-compared-to-earth/#ixzz2Q4WAXjjX (Information on size of the earth & moon)