2)Find the force of gravity between a tub of water (751.7 kg) and the Sun. The Sun’s mass is 1.99 x 1030 kg and is 1.50 x 1011 m away.
I'm guessing you multiple the sun's mass by 9.8(N/kg) .. then what?
Your guess is way off the mark. Try reading your text instead of guessing.
You need to review Newton's universal law of gravity.. the one with the factor G in it. . I provided the equation in the answer to one of your other posts.