Your parents bought your little brother a sandbox in the shape of a rectangular prism for his birthday. The dimensions are a length of 24 inches, height of 8 inches, and a width of 16 inches. Your parents only want to fill the sandbox up to 75% capacity to stop it from spilling out. How much sand do your parents need to buy? What is the total volume of the sandbox? How much sand would your parents need to buy? (75% of the total volume)