- Mr Ausome

# Use your Calculator to Calculate Standard Deviation

After a tedious and lengthy process of calculating the **standard deviation **using the formula, you are uncertain whether your final answer is correct. After all, it involves a dozen of complicated steps and you could have made a typo in any one of them. That one careless mistake in the sea of working could result in you losing the 2-3 marks allocated to finding this trouble maker called **standard deviation**.

Fortunately, our best buddy (Mr Calculator) is capable of churning out the standard deviation quickly. Time to learn how to make full use of your **calculator** to calculate the standard deviation!

*Note: The calculator can only be used for checking of answers! You are still required to show your working to get the method marks in your math exams!*

**Using Calculator ****Casio fx-96SG PLUS**** to Calculate Standard Deviation**

Step 1: Activate Frequency Column

(You only need to do this once as long as you don’t reset your calculator)

Step 2: Change to Stat Mode

Step 3: Input Data

Type and enter the x-values/frequency using the number buttons and equal button.

Use the arrow keys to move around.

Once the full set of data has been entered, press

Step 4: Obtain Standard Deviation

**Example:**

A group of 100 students in Singapore were asked the number of hours that they spend on

every week. The results are given in the table below.

Using the **calculator** method shown above, find the** standard deviation **of the number of hours that these students in Singapore spend on math tuition.

**Answer: 1.09**

Hint: Use the mid-value of the data for when keying in "x". (use 0.5 for first row, 1.5 for second row etc.)

*“Patience, persistence and perspiration make an unbeatable combination for success.” ~ Napoleon Hill*

**Math Specialist**

**Mr Ausome**