[Solved] Refer to Figure 13-5. What is the amount of machine time for model P-4 in terms of percent of a machine hour? A) 10% B) 20% C) 25% D) 30% E) 50% Reproductive Potential: The biological capability of an individual or species to produce offspring, contributing to the genetic diversity of a population. Erotic Plasticity: The degree to which an individual's sex drive can be changed by social, environmental, and situational factors. Fraternal Birth-Order Effect: The observation that a man is more likely to be homosexual the more older brothers he has from the same mother. Older Brothers: Typically refers to male siblings who are born before other children in a family, often associated with roles of protection, mentorship, and influence in the sibling relationship.