Question: which method of forecasting uses averages to predict future weather

title: Forecasting
text: Seasonality is a characteristic of a time series in which the data experiences regular and predictable changes which recur every calendar year . Any predictable change or pattern in a time series that recurs or repeats over a one - year period can be said to be seasonal . It is common in many situations -- such as grocery store or even in a Medical Examiner 's office -- that the demand depends on the day of the week . In such situations , the forecasting procedure calculates the seasonal index of the `` season '' -- seven seasons , one for each day -- which is the ratio of the average demand of that season ( which is calculated by Moving Average or Exponential Smoothing using historical data corresponding only to that season ) to the average demand across all seasons . An index higher than 1 indicates that demand is higher than average ; an index less than 1 indicates that the demand is less than the average . 

Answer: answer: Seasonality, in which data experiences regular and predictable changes which recur every calendar year, is the method of forecasting, where averages are used to calculate the seasonal index of the season.