## What Is the 2 Sigma?

**Sigma **refers to the **Population Standard Deviation**. The formula for **Sigma **is:

**Sigma = âˆš(x-Âµ)**

^{2}/N**N = Population Size
**

**ÂµÂ = Population Mean**

**x = Each Value from Population**

The formula for **2 Sigma** becomes:

**2 Sigma = 2 * Sigma**

The dataset contains students’ **Name** and **Obtained Marks**.

### Method 1 – Use a Generic Formula to Determine the 2 Sigma in Excel

Find **Population Size (N)**, **Population Mean (Âµ)**, **x-Âµ**, and **(x-Âµ)**** ^{2 }**and calculate

**Sigma**and

**2 Sigma**.

#### Step 1: Calculate Population Size

- Select a cell to calculate the
**Population Size**. Here,**D12**. - In
**D12**enter the following formula.

`=COUNT(C5:C10)`

- Press
**Enter**to see the**Population Size (N)**.

**the COUNT function**,

**C5:C10**is selected as values. The formula returns the number of entries in the selected range.

#### Step 2: Find Population Mean

Find the **Population Mean** for the dataset.

- Select a cell to see the
**Population Mean**. - Enter the following formula in that cell.

`=AVERAGE(C5:C10)`

- Press
**Enter**to see the result.

**the AVERAGE function**,Â

**C5:C10**is selected as numbers. The formula returns the average of these numbers.

#### Step 3: Determine x-Âµ

Determine** x-Âµ **for every student.

- Select a cell to calculate
**x-Âµ**. Here,**Â D5**. - In
**D5,**enter the following formula.

`=C5-$D$13`

- Press
**Enter**to see the result.

**Population Mean**from the

**Obtained Marks**. An

**Absolute Cell Reference**for

**Population Mean**was used, so that it remains fixed while using

**Autofill**.

- Drag down the Fill Handle to see the result in the rest of the cells.

- This is the output.

#### Step 4: Calculate (x-Âµ)^2

Calculate the **(x-Âµ)**** ^{2}** for each student.

- Select a cell to see the
**(x-Âµ)**.^{2} - Enter the following formula.

`=D5^2`

- Press
**Enter**to see the result.

**raises**the value in

**D5**to the

**power of 2**.

- Drag down the Fill Handle to see the result in the rest of the cells.

#### Step 5: Find the Sigma

Find the **Sigma** for the **Obtained Marks**.

- Select a cell to see the
**Sigma**. Here,**Â D14**. - Enter the following formula.

`=SQRT(SUM(E5:E10)/D12)`

- Press
**Enter**to see the**Sigma**.

**Formula Breakdown**

**SUM(E5:E10):**In**the SUM function**Â**E5:E10**is selected as**numbers**. The formula returns the**summation**of**E5:E10**.**SUM(E5:E10)/D12:**This formula divides the**summation**by**D12**.**SQRT(SUM(E5:E10)/D12):****The SQRT function**returns the square root of the result.

#### Step 6: Calculate the 2 Sigma

- Select a cell to see the
**2 Sigma**. - Enter the following formula in the selected cell.

`=2*D14`

- Press
**Enter**and you will see the**2 Sigma**.

**multiplies**the

**Sigma**by

**2**and returns the result.

**Read More:**How to Calculate Sigma Level in Excel

### Method 2 – Applying the STDEV.P Function to Calculate the 2 Sigma in Excel

Use **the STDEV.P function** to **calculate the 2 Sigma**.

**Steps:**

- Select the cell to see the
**Sigma**. - Enter the following formula.

`=STDEV.P(C5:C10)`

- Press
**Enter**to see the result.

**STDEV.P**function,

**C5:C10**is selected as

**numbers**. The formula returns the

**Standard Deviation**in the range: the

**Sigma**.

- Select a cell to see the
**2 Sigma**. Here,**C13**. - Enter the following formula.

`=2*C12`

- Press
**Enter**to see the**2 Sigma**.

**multiply**the

**Sigma**by

**2**.

## Practice Section

Practice here.

**Download Practice Workbook**

Download the practice workbook.

## Related Article

**<< Go Back to Calculate Sigma in Excel |Â Excel for StatisticsÂ |Â Learn Excel**