Tess builds a sandbox in the shape of a regular hexagon in which all the sides are 40 inches long. She then takes a photo of the sandbox and prints the photo. In the photo, the sides of the hexagon are each 4 inches long. Identify the scale factor that was used to create the printed photo of the sandbox. Express your answer as a decimal.

The scale factor of the printed photo of the sandbox is 4 inches / 40 inches = <<4/40=0.1>>0.1. Answer: \boxed{0.1}.