I am very confused about how to do this problem. I know I multiply the first three numbers but I am unsure what to do nextA rectangular waterbed is 8 ft long, 4 ft wide, and 2 ft tall.How many gallons of water are needed to fill the waterbed?Assume 1 gallon is 0.13 cu ft. Round to the nearest whole gallon.

The first thing is to calculate the volume of the waterbed, since it is a rectangular prism, the volume is the product of its length, width and height.

[tex]\begin{gathered} V=8\cdot4\cdot2 \\ V=64ft^3 \end{gathered}[/tex]

Knowing the volume in cubic feet, we can convert this value to gallons thanks to the conversion factor, where 1 gallon is equal to 0.13 cubic feet.

We perform the operation, just like this:

[tex]\begin{gathered} 64ft^3\cdot\frac{1\text{ gal}}{0.13ft^3}=492.30\text{ gal} \\ 492.30\text{ gal }\cong492\text{ gal} \end{gathered}[/tex]

Therefore a total of 492 gallons are needed.