math formula / spherical geometry for sculpture

I'm looking for a formula to calculate if it is possible to create a mono-monostatic body out of a miniature rubber basketball and an acrylic tube of a variable length. I have PUR casting resin that I would like to fill the basketball with but it is rather expensive and I'd rather not use it until I know if it will be able to weigh down the ball and create a mono-monostatic body like a roly-poly toy. The cast resin has a density of roughly 1.1 g/cm³. The acrylic tube has an outer diameter of 150 mm and an inner diameter of 144mm with a density of 1.18 g/cm3 and a variable length. The basketball weighs 306 grams un-inflated and 310 grams when fully inflated. When inflated the ball has a circumference of 560 mm. The ball will be inserted into the tube at it's equator and inflated to the circumference of the tube. So when fully inflated it becomes kind of oblong sphere with one diameter true to the basketball and one diameter true to the acrylic tube. I will inject the mixed resin into the ball and it will rest at the bottom. My question is how much resin do I need for different lengths of tube / is it possible at all? For the project to be compete I would need an explanation of the math and a formula where I can change the amount of resin and the length of the tube and see if the combination of the parts will stand vertical on the ball or if it will fall over.