The density of the mixture will be 1.57 g/cm³.
Step 1. Calculate the mass of the butter.
[tex]\text{Mass} = \text{1.00 cm}^{3 } \times \frac{\text{0.680 g} }{\text{1 cm}^{3 }} = \text{0.860 g}\\[/tex]
Step 2. Calculate the mass of the sand.
[tex]\text{Mass} = \text{1.00 cm}^{3 } \times \frac{\text{2.28 g} }{\text{1 cm}^{3 }} = \text{2.28 g}\\[/tex]
Step 3. Calculate the density of the mixture.
Total mass = 0.860 g + 2.28 g = 3.14 g.
Total volume = 1 cm³ + 1 cm³ = 2 cm³
[tex]\text{Density} = \frac{\text{mass}}{\text{volume}} = \frac{\text{3.14 g} }{\text{2 cm}^{3 }} = \textbf{1.57 g/cm}{^{3}\\[/tex]
