East Carolina University doesn't provide an average SAT score for its admitted students in a single, readily available figure like some other universities. Their admissions information focuses more on high school GPA and class rank. This is because ECU uses a holistic review process, considering many factors beyond just standardized test scores.
To find a general idea, you might try looking at sites like CollegeData or Peterson's which compile data from various sources, but keep in mind that those numbers are usually estimates and may not be perfectly up-to-date. The information you find on those sites will probably give you a range, rather than a precise average.