Your question is Testing Engagement Change for Noise. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
You are reviewing a change in user engagement after a product update. The team wants to know whether the observed shift is a real effect or just random variation in the data.
What statistical methods would you use to decide whether a change in user engagement is real or just noise?