Answer:
If an item floats, Then it is less dense than the liquid it floats in. One can prove this using bernoulli's equation. To determine the weight of the floating object, take the volume of water displaced by the portion of the object below the fliud surface then multiply that by the density of the fluid. This process gives you the bouyant force on the floating object and therefore the weight. Then take that weight and divide it by the total volume of the. Object to get its density.
Also note that if an item is suspended below the surface but. Above the bottom of the fluid body, then the item and fluid have equal density.
If the item sinks to the bottom it has higher density than the fluid.