Volumetric expansion coefficients of simple materials are often well cataloged. However, the thermal expansion coefficient of a human body is less well known. This could affect the human body's specific gravity and, therefore, measurements of its body‑fat ratio. Suppose that a human body of weight 0 on dry land is placed on a scale while completely immersed in formaldehyde of temperature 1. Once the temperature increases by Δ, the scale reading drops by Δ. Derive an expression for in terms of Δ, 0, and Δ by assuming that the ratio of the density of formaldehyde f and the initial density of the body b is =f/b. Assume also that f does not change when heated.