An office manager forecasts demand for office stationery by exponential smoothing, with alpha = 0.4. Actual demand two weeks ago (i.e., the week before last) was 12 boxes, but the forecast for that period was only 10. Actual demand last week was 7. What was the forecast for last week?
a) 7.4 boxes
b) 8.4 boxes
c) 9.4 boxes
d) 10.4 boxes