Final answer:
The forecasted demand for Year 9 using a 4-period moving average is calculated by averaging the demand from Year 5 through Year 8, resulting in a forecast of 325.
Step-by-step explanation:
To forecast demand for Year 9 using a 4-period moving average, we take the average of the demand from the last four years provided (Years 5 through 8). Calculating this, we have:
(Year 5 + Year 6 + Year 7 + Year 8) / 4 = (300 + 330 + 380 + 290) / 4 = 1300 / 4 = 325
So, the forecasted demand for Year 9 using a 4-period moving average is 325.