$$ \text{Engagement} = \text{Relatability} + \text{Emotional Connection} + \sum (\text{Intrigue} + \text{Adventure} + \text{Personal Growth}) $$
This equation suggests that engagement is a sum of how relatable the story is, the emotional connection it fosters, and the accumulation of intrigue, adventure, and personal growth elements throughout the narrative.
In terms of mathematical representation, if we were to consider a formula for engagement based on the elements discussed:
