# FORECAST

## Content

This function calculates a future value using existing values.

## Syntax

`FORECAST(value, Yarray, Xarray)`

## Arguments

This function has these arguments:

| Argument | Description |
| -------- | ----------- |
| *value* | [Required] Value for which to predict the future dependent value |
| *Yarray* | [Required] An array of known dependent values (y’s) |
| *Xarray* | [Required] An array of known independent values (x’s) |

## Remarks

The predicted value is a y value for a given x value. The known values are existing x values and y values, and the new value is predicted by using linear regression. You can use this function to predict future sales, inventory requirements, or consumer trends.
This function is calculated as follows:
![](https://cdn.mescius.io/document-site-files/images/8d606653-16a0-474d-b9dc-e2b4d01c2446/images/Func-FORECAST.png)
where v is the *value* argument, Y is the *Yarray* argument, X is the *Xarray* argument, and n is the size of the arrays.

## Examples

`FORECAST(30,G1:G9,F1:F9)`
`FORECAST(30,R1C7:R9C7,R1C6:R9C6)`
`FORECAST(45,{53000,57000,58000,69000,74500,55620,80000, 68700},{35,31,47,51,37,31,58,39})` gives the result 67060.8665320360