Final answer:
The best representation of the average rate at which human hair grows is 0.25 inches per month. Human hair grows in a cycle of active growth, transition, and rest phases, with an average daily growth rate and periodic replacement of hairs.
Step-by-step explanation:
The average rate at which human hair grows is approximately 0.25 inches per month. This equates to about half an inch (1.25 cm) each month or around 6 inches (15 cm) annually. Human hair growth occurs through a cycle that includes the anagen phase, where hair growth is most active, the catagen phase, a transitional stage, and the telogen phase, a rest period. Over these cycles, an average of 50 hairs are lost and replaced each day. The growth rate of human hair is similar to the motion of the plates of the earth, which also average at a rate comparable to hair growth.