In a corporate environment, a security analyst is tasked with implementing a behavioral analytics solution to detect anomalies in user behavior. The system is designed to establish a baseline of normal user activity over a period of time. After monitoring for three weeks, the system identifies that a particular user has accessed sensitive files at an unusual frequency, deviating significantly from their established baseline. The analyst needs to determine the threshold for flagging this behavior as anomalous. If the baseline access frequency for sensitive files is calculated to be 5 accesses per week with a standard deviation of 2, what threshold should the analyst set to ensure that only significant deviations are flagged?