Your question is Testing a Conversion Rate Drop. 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 notice that a feature's conversion rate is lower after a change, and you need to decide whether the drop reflects real performance degradation or normal sampling noise. You are asked how you would evaluate that change statistically.
If a feature's conversion rate drops by 5%, what statistical tests would you perform to determine if the change is significant?