Answer:
A ratio of equivalent units
Explanation:
A conversion factor is a ratio of equivalent units and depends on which units are to be converted.
For example we want to convert 275 [mm] to inches, so we have to find the right conversion factor to allow us to work that conversion.
275 [mm] = inches = ?
[tex]275 [mm] * \frac{1in}{25.4mm} = 10.82 [in][/tex]
In this case the ratio is 1/25.4 = 0.039 [in/mm]
