# How to Use DEVSQ in Excel (With Example)

You can use the DEVSQ function in Excel to calculate the sum of squares of deviations for a given sample.

This function uses the following basic syntax:

`=DEVSQ(value1, value2, value3, ...)`

Here’s the formula that DEVSQ actually uses:

Sum of squares of deviations = Σ(xix)2

where:

• xi: The ith data value
• x: The sample mean

The following example shows how to use this function in practice.

## Example: How to Use DEVSQ in Excel

Suppose we have the following dataset in Excel: We can use the following formula to calculated the sum of squares of deviations for this dataset:

`=DEVSQ(A2:A13)`

The following screenshot shows how to use this formula in practice: The sum of squares of deviations turns out to be 319.

We can confirm this is correct by manually calculating the sum of squares of deviations for this dataset.

Note: The average value of this dataset is 9.5.

Knowing this, we can simply plug in the values from the dataset into the formula for sum of squares of deviations:

• Sum of squares of deviations = Σ(xix)2
• Sum of squares of deviations = (2-9.5)2 + (3-9.5)2 + (5-9.5)2 + (5-9.5)2 + (7-9.5)2 + (8-9.5)2 + (9-9.5)2 + (12-9.5)2 + (14-9.5)2 + (15-9.5)2 + (16-9.5)2 + (18-9.5)2
• Sum of squares of deviations = 56.25 + 42.25 + 20.25 + 20.25 + 6.25 + 2.25 + 0.25 + 6.25 + 20.25 + 30.25 + 42.25 + 72.25
• Sum of squares of deviations = 319

The sum of squares of deviations turns out to be 319.

This matches the value that we calculated using the DEVSQ function.