Water has a molecular weight of 18 g/mol. Acetone is heavier, at 58 g/mol. Basically, for the same number of water and acetone molecules, the acetone is 3.22 times heavier (58 / 18 = 3.22).
As temperature of liquid acetone goes up under constant pressure, acetone volume decreases in almost-linear fashion. Most liquids exhibit decreased density with increased temperature.
There is a maximum density at 4 degrees Celsius. This density peak means that between 0 Celsius (freezing point) and 4 Celsius, water density increases with temperature.
Hydrogen bonding weakly attracts molecules. Water’s low molecular mass and easily-packed geometry (V-shape) allows a closer average spacing between molecules up to 4 Celsius. Above 4 Celsius, molecular kinetic energy overcomes hydrogen bonding, accounting for the typical density decrease.
Practically, water and liquid acetone evaporation rates should be taken into account. Experiments with identical beakers, pure acetone/water, and sensitive enough weight measurements recorded over time can be done to confirm loss of liquid acetone mass faster than liquid water mass.