The image above represents standard deviation.

To compute for standard deviation, three essential parameters are needed and these parameters are **Number of possible outcomes in any single trial (n), Probability of a success in any single trial (p) **and **Probability of a failure in any single trial (q).**

The formula for calculating standard deviation:

σ = √(npq)

Where;

σ = Standard deviation

n = Number of Possible Outcomes in Any Single Trial

p = Probability of a Success in Any Single Trial

q = Probability of a Failure in Any Single Trial

Let’s solve an example;

Find the standard deviation when the number of possible outcomes in any single trial is 14, the probability of a success in any single trial is 0 and the probability of a failure in any single trial is 1.

This implies that;

n = Number of Possible Outcomes in Any Single Trial = 14

p = Probability of a Success in Any Single Trial = 0

q = Probability of a Failure in Any Single Trial = 1

σ = √(npq)

σ = √((14)(0)(1))

σ = √(0)

σ = 0

Therefore, the **standard deviation** is **0.**

**Calculating for Number of Possible Outcomes in Any Single Trial when the Standard Deviation, the Probability of a Success in Any Single Trial and the Probability of a Failure in Any Single Trial is Given.**

n = ^{σ2} / _{pq}

Where;

n = Number of Possible Outcomes in Any Single Trial

σ = Standard deviation

p = Probability of a Success in Any Single Trial

q = Probability of a Failure in Any Single Trial

Let’s solve an example;

Given that standard deviation is 5, the probability of a success in any single trial is 1 and the probability of a failure in any single trial is 1. Find the number of possible outcomes in any single trial?

This implies that;

σ = Standard deviation = 5

p = Probability of a Success in Any Single Trial = 1

q = Probability of a Failure in Any Single Trial = 1

n = ^{σ2} / _{pq}

n = ^{52} / _{1 x 1}

n = ^{25} / _{1}

n = 25

Therefore, the **number of possible outcomes in any single trial** is **25.**

**Calculating for Probability of a Success in Any Single Trial when the Standard Deviation, the Number of Possible Outcomes in Any Single Trial and the Probability of a Failure in Any Single Trial is Given.**

p = ^{σ2} / _{nq}

Where;

p = Probability of a Success in Any Single Trial

σ = Standard deviation

n = Number of Possible Outcomes in Any Single Trial

q = Probability of a Failure in Any Single Trial

Let’s solve an example;

Given that standard deviation is 2, the number of possible outcomes in any single trial is 2 and the probability of a failure in any single trial is 1. Find the probability of a success in any single trial?

This implies that;

σ = Standard deviation = 2

n = Number of Possible Outcomes in Any Single Trial = 2

q = Probability of a Failure in Any Single Trial = 1

p = ^{σ2} / _{nq}

p = ^{22} / _{2 x 1}

p = ^{4} / _{2}

p = 2

Therefore, the **probability of a success in any single trial** is **2.**

**Calculating for Probability of a Failure in Any Single Trial when the Standard Deviation, the Number of Possible Outcomes in Any Single Trial and the Probability of a Success in Any Single Trial is Given.**

q = ^{σ2} / _{nq}

Where;

q = Probability of a Failure in Any Single Trial

σ = Standard deviation

n = Number of Possible Outcomes in Any Single Trial

p = Probability of a Success in Any Single Trial

Let’s solve an example;

Given that standard deviation is 3, the number of possible outcomes in any single trial is 2, the probability of a success in any single trial is 1. Find the probability of a failure in any single trial?

This implies that;

σ = Standard deviation = 3

n = Number of Possible Outcomes in Any Single Trial = 2

p = Probability of a Success in Any Single Trial = 1

q = ^{σ2} / _{nq}

q = ^{32} / _{2 x 1}

q = ^{9} / _{2}

q = 4.5

Therefore, the **probability of a failure in any single trial **is **4.5.**

Nickzom Calculator – **The Calculator Encyclopedia** is capable of calculating the standard deviation.

To get the answer and workings of the standard deviation using the **Nickzom Calculator – The Calculator Encyclopedia. **First, you need to obtain the app.

You can get this app via any of these means:

**Web** – https://www.nickzom.org/calculator-plus

To get access to the **professional **version via web, you need to **register** and **subscribe **for** NGN 1,500 **per** annum** to have utter access to all functionalities.

You can also try the **demo **version via https://www.nickzom.org/calculator

**Android (Paid)** – https://play.google.com/store/apps/details?id=org.nickzom.nickzomcalculator

**Android (Free)** – https://play.google.com/store/apps/details?id=com.nickzom.nickzomcalculator

**Apple (Paid)** – https://itunes.apple.com/us/app/nickzom-calculator/id1331162702?mt=8

Once, you have obtained the calculator encyclopedia app, proceed to the **Calculator Map, **then click on **Probability**** **under **Mathematics****.**

Now, Click on **Standard Deviation**** **under **Probability**

The screenshot below displays the page or activity to enter your values, to get the answer for the standard deviation according to the respective parameters which are the **Number of possible outcomes in any single trial (n), Probability of a success in any single trial (p) **and **Probability of a failure in any single trial (q).**

Now, enter the values appropriately and accordingly for the parameters as required by the **Number of possible outcomes in any single trial (n)** is **14**,** Probability of a success in any single trial (p) **is **0 **and **Probability of a failure in any single trial (q)** is **1**.

Finally, Click on Calculate

As you can see from the screenshot above, **Nickzom Calculator**– The Calculator Encyclopedia solves for the standard deviation and presents the formula, workings and steps too.