Final answer:
The question is possibly misstated since it refers to Fried's rule which involves calculating medication dosages but then delves into probability calculations for different scenarios involving children.
Step-by-step explanation:
The question asked pertains to Fried's rule, a mathematical formula used in medicine, specifically in the context of pediatric radiology, to estimate medication dosages for children. However, the information provided does not directly refer to Fried's rule but instead discusses various scenarios that involve calculating probabilities related to children's age or activities. It seems the question may have been misunderstood or misstated. Hence, I cannot provide an answer related to Fried's rule without the correct information on what is being divided in the rule. The provided scenarios, like calculating the probabilities of an eight-week-old baby smiling or a nine-year-old child eating a doughnut for a certain duration, involve conditional and discrete probability calculations within the mathematics discipline, and these scenarios are typically covered in high school curriculum.