Final answer:
A forecast using the latest observation in a sequence to predict the next period is called a naïve forecast, which is a straightforward approach relying on the most recent data point.
Step-by-step explanation:
Using the latest observation in a sequence of data to forecast the next period is known as a naïve forecast. This method assumes that the most recent observation is the simplest possible predictor for the next period. It doesn't involve any complex modeling or smoothing techniques like moving averages or exponential smoothing, which take into account more than one previous data point.
Instead, it uses just one data point and hence is straightforward and easy to apply, especially when data shows little variability or when historical information isn't considered reliable for forecasting.