The Naïve forecast method uses the most recent observation as the forecast for the next period. In this case, to forecast the time series value for Week 3, we would use the actual value from Week 2.
From the data provided:
- Week 1: 13
- Week 2: 16
- Week 3: 14
- Week 4: 16
The forecast for Week 3 using the Naïve forecast method would be the value from Week 2, which is 16.