The obvious answer is because propane is a gas at room temperature, while 2-propanol is a liquid at room temperature.
That happens because the intermolecular forces that exist between 2-propanol, or isopropyl alcohol, molecules are stronger than those that exist between propane molecules.
The nearest ten thousand of 63849 would be 60000
28/20 in simplest form is: 7/5
70/50 in simplest form is 5/7
Because,
28/20 divided by 2 is 14/10, divided by 2 again is: 7/5
70/50 divided by 2 is 25/35, divided by 2 again is: 5/7