To begin, density is found with the formula "mass/volume." Question has already given you a mass of 176 grams. Next you must find the volume. To do so you must cube the length of one edge of the given aluminum cube which is four centimeters. (4cm×4cm×4cm=64cm^3) This is your cube's volume and now you can divide. Start with putting 176g/64cm^3 and you should get 2.75g/cm^3. With correct significant numbers your answer doesn't change.
