The FORECAST function is used predict a future value with the existing values. This function can be used to predict future sales, inventory requirements, consumer trends, etc based on the relationship between the given two sets of values. Note: This prediction is calculated based on the assumption of a Linear Trend.
=FORECAST (Item to Forecast, Range Y, Range X) Whereas "Item to Forecast" is a point in the future (or past) which we need to forecast, "Range Y" is the historical data to be used as the base for forecast and "Range X" is the interval used while recording the historical data (like month)
Let us predict a value, using the FORECAST function, with the help of the below video