This article describes the formula syntax and usage of the SUMXMY2 function in Microsoft Excel.
Description
Returns the sum of squares of differences of corresponding values in two arrays.
Syntax
SUMXMY2(array_x, array_y)
The SUMXMY2 function syntax has the following arguments:

Array_x Required. The first array or range of values.

Array_y Required. The second array or range of values.
Remarks

The arguments should be either numbers or names, arrays, or references that contain numbers.

If an array or reference argument contains text, logical values, or empty cells, those values are ignored; however, cells with the value zero are included.

If array_x and array_y have a different number of values, SUMXMY2 returns the #N/A error value.

The equation for the sum of squared differences is:
Example
Copy the example data in the following table, and paste it in cell A1 of a new Excel worksheet. For formulas to show results, select them, press F2, and then press Enter. If you need to, you can adjust the column widths to see all the data.
Data 

First array 
Second array 

2 
6 

3 
5 

9 
11 

1 
7 

8 
5 

7 
4 

5 
4 

Formula 
Description (Result) 
Result 
=SUMXMY2(A3:A9,B3:B9) 
Sum of squares of differences of the two arrays above (79) 
79 
=SUMXMY2({2, 3, 9, 1, 8, 7, 5}, {6, 5, 11, 7, 5, 4, 4}) 
Sum of squares of differences of the two arrays constants (79) 
79 