Compute specialty spend share and top age band

You are working with a health-plan dataset whose member records live in two separate tables, mem1 and mem2. Each of them stores member_id (a primary key) and an age_band label, and no member identifier shows up in both. Claim lines are stored in claim, with columns claim_id (primary key), member_id, specialty, paid_amt, and claim_date; a claim's member_id can be resolved against either member table. A risk table exists as well, but the tasks below do not depend on it. Treat…