GATE 2022 PI – Question 65
Weekly oxygen-cylinder demand is forecast using exponential smoothing, α = 0.2. Actual demands in weeks 1–4 are 375,412,592,439; forecast for week 3 is 500. Find week-5 forecast in units (integer).
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Correct answer: 500 to 505
Explanation
Use $F_{t+1}=\alpha A_t+(1-\alpha)F_t$. Thus F₄ = 0.2×592+0.8×500 = 518.4. Then F₅ = 0.2×439+0.8×518.4 = 502.52, rounding to **503 units**. Weeks 1–2 are unnecessary once F₃ is given.