Final answer:
The Apgar score is a method used to evaluate the general well-being of a newborn. Based on the given observations, the respiratory therapist should assign an Apgar score of 6 to the infant.
Step-by-step explanation:
The Apgar score is a method used to evaluate the general well-being of a newborn and assess its transition from the uterus to the outside world. It consists of five criteria: appearance (skin color), pulse (heart rate), grimace (reflex), activity (muscle tone), and respiration. Each criterion is assigned a score of 0, 1, or 2, and the scores are added together to obtain the Apgar score. In this case, based on the given observations, the respiratory therapist should assign an Apgar score of 6 to the infant.