The combined mean of two groups of sizes n₁ and n₂ with means x̄₁ and x̄₂ is given by: MCQ with Answer and Explanation

Explanation:
Fisher's index fails the Circular Test. Only indexes with constant weights, like Kelly's or simple geometric mean of price relatives, pass it.

Explanation:
Net Reproduction Rate (NRR) accounts for female mortality before reaching the end of the reproductive period.

Explanation:
Using Bayes' theorem: P(B|Defective) = [P(Defective|B) × P(B)] / [Σ P(Defective|machine) × P(machine)] = (0.03×0.45) / (0.02×0.30 + 0.03×0.45 + 0.04×0.25) = 0.0135 / 0.0315 ≈ 0.4286 ≈ 0.43.