what is the estimated difference between americans that experience some form of sexual harassment and those that tell someone?

Direct answer first: The gap between the share of Americans who experience some form of sexual harassment and the share who report or tell someone about it is substantial and varies by context (workplace, school, public life). Across large national surveys, a common pattern is that a large majority report having experienced some form of harassment, while a much smaller share actually tells someone—the discrepancy is driven by fear, shame, normalization of harassment, concern about retaliation, and skepticism about consequences. Precise figures depend on the population and definition used, but typical estimates place lifetime harassment experience well over 40–80% for women in various settings, while only a minority report or disclose their experience to someone (often on the order of a fraction to a bit over one-third in some populations). For men the prevalence is lower, and disclosure is correspondingly lower or similar in absolute terms. If you’d like, I can pull current, specific figures from recent surveys (e.g., NSVRC, RAINN, EEOC) and break them down by setting (workplace vs. educational environments) and by gender, with sources and exact percentages.