The FORECAST.LINEAR function in Google Sheets allows you to predict future values in a linear trendline. To use the function, you first need to create a linear trendline for your data. Once you have created the trendline, you can use the FORECAST.LINEAR function to predict future values. The function takes four arguments: the data point, the slope, the intercept, and the number of periods. The data point is the value you want to predict, the slope is the rate of change in the data, the intercept is the value where the trendline crosses the y-axis, and the number of periods is the number of periods over which the trendline is calculated.
The syntax of FORECAST.LINEAR in Google Sheets is as follows: =FORECAST.LINEAR(y_values,x_values,intercept) where y_values is the array of data points for which you want to predict a linear trend, x_values is the array of corresponding x-values, and intercept is the desired y-intercept for the trend line.
One example of how to use FORECAST.LINEAR in Google Sheets is to predict future sales based on historical sales data. In order to do this, you would need to have a column in your spreadsheet that includes the sales data for each month, and then you would use the FORECAST.LINEAR function to predict the sales for the next month. The function takes four parameters: the first is the range of cells that contains the historical data, the second is the number of periods in the historical data, the third is the cell in the range that you want to predict, and the fourth is the cell in the range that you want to predict the error for.
There are a few occasions when you might not want to use the FORECAST.LINEAR function in Google Sheets. One example might be when you have a series of data points that are not linearly related. In this case, the FORECAST.LINEAR function would not be the most accurate predictor of future values. Another time you might not want to use the FORECAST.LINEAR function is when you have a series of data points that are not evenly spaced. In this case, the linear regression line would not be a good predictor of future values.
There are a few similar formulae to FORECAST.LINEAR in Google Sheets. One is FORECAST.PRECISE, which gives you a more precise forecast than FORECAST.LINEAR. The formula uses a number of factors, such as the trend of the data and the number of periods you specify, to calculate a more accurate forecast. Another similar formula is FORECAST.QUARTILE, which calculates quartiles for your data set and uses them to predict future values. This formula is useful for identifying which values are most likely to occur in your data set. Finally, there is FORECAST.EXPONENTIAL, which uses an exponential decay function to predict future values. This formula is useful when you have data that follows a decaying trend.