Write out the given volume
Define scale factor
The scale factor of two similar shapes can be defined as the ratio of the length of the initial shape to the length of the final shape.
Find the ratio of the Volume
The ratio of the volume of the smaller pyramid to the larger pyramid is
State the relationship between the volume of a pyramid to the length
The unit of measure of the volume is the cube of the length (for example if the unit of the length is inches, the unit of the volume would be cubic inches). While the unit of the length is the cube root of the unit of the volume
Find the ratio of the length
The ratio of the length would be the cube root of the ratio of the volume
Since the scale factor is the ratio of the length,
Hence, the scale factor is 3/7