## Elementary Technical Mathematics

$44\ ft^3$ sand
Create a proportion using ratios of sand:concrete. $\frac{2.75\ ft^3\ sand}{8\ ft^3\ concrete}=\frac{x\ ft^3\ sand}{128\ ft^3\ concrete}$ Set the product of the means equal to the product of the extremes and solve for the variable. $8 \times x=2.75\times 128$ $8x=352$ $8x\div8=352\div8$ $x=44$