Excel 2000 in a Nutshell

Name

GROWTH

Synopsis

Use GROWTH to predict the exponential growth for the y-axis values based on the known y-axis and x-axis values. This function returns an array of values that indicates the predicted y-axis values, and therefore it must be specified as an array formula. The function determines the values based upon the equation y=b*m^x.

Specifying Values in an Array

When you specify an array of values the values can exist in one column or in multiple columns. If you manually type the values of the array you need to use a comma (,) to separate each value in a column and a semicolon (;) to separate the columns.

To Calculate

=GROWTH(Known_Y's, Known_X's, New_X's, Const)

The Known_Y's argument is required for this function. All other arguments are optional.

Known_Y's

This array must contain a series of positive numbers. If the values in the array are in a single column, then the function interprets the values in each column of the Known_X's as a separate variable. If the values in the array are in a single row then the function interprets the values in each row of the Known_X's array as a separate variable.

Known_X's

If this argument is omitted, it is assumed to be an array of values in the range of {1,2,3,...} that is the same size as the array specified by the Known_Y's argument.

New_X's

Indicates the new x-axis values for which you want to find the corresponding y values. If these values are omitted, they are assumed to be the same as the Known_X's argument.

Example

Figure 15-20 illustrates ...