lesson 5 of 5 · mission: statistical sanity checklesson 5 of 5 · mission: statistical sanity checklesson 5 of 5 · mission: statistical sanity checklesson 5 of 5 · mission: statistical sanity checklesson 5 of 5 · mission: statistical sanity checklesson 5 of 5 · mission: statistical sanity checklesson 5 of 5 · mission: statistical sanity checklesson 5 of 5 · mission: statistical sanity checklesson 5 of 5 · mission: statistical sanity checklesson 5 of 5 · mission: statistical sanity checklesson 5 of 5 · mission: statistical sanity check
Write headline(data) — the one-line verdict at the top of every sanity report. Return (don't print inside the function) the string "n=... pos_rate=... baseline=..." with both percentages formatted :.1%. Print it for the 6-row dataset.