Welcome to your interview.
The question is on your right: Loss Ratio with Window Functions. Take a moment with it first.
Talk your thinking through with me if you like - when you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes). Discussion and graded submissions share your five interviewer interactions, so spend them well.
Given a SQL database of insurance policies and claims, write a query using window functions to calculate the cumulative loss ratio per region over time.