Compute the two branch z-scores, the 95 % empirical-rule band for Branch A, and the coefficient of variation of the six audit-hour totals.

Answer

import statistics as st z_a = (52 - 45) / 5 z_b = (60 - 50) / 8 print(f"z_A={z_a:.2f} z_B={z_b:.2f}") print(f"band95=({45 - 2 * 5}, {45 + 2 * 5})") hrs = [42, 38, 51, 45, 39, 49] print(f"CV={st.stdev(hrs) / st.mean(hrs):.4f}")

IBS1 §2.7 (z-scores across groups; Chebyshev beside the empirical rule), IS1 §2.7, CC BY 4.0 — shape only; original scenario