# How to Calculate Mean & Standard Deviation by Calculator (Casio fx-96SG PLUS)

/These are the instructions to calculate mean & standard deviation by the Casio fx-96SG PLUS calculator.

It works on the older Casio fx-95SG PLUS calculator as well.

For those taking O Level Mathematics (E Maths), take note that you still have to apply the formula and show full workings when calculating mean and standard deviation.

Use the calculator to check your answer.

**Important buttons**

Pay attention to the following buttons:

1. The leftmost button **SHIFT**. We use this button to assess the alternative commands of the other buttons.

2. The directional buttons (▲ ▼ ◄ ►) at the center.

3. The button **MODE** which is second from the right.

**Step 1: Enable the Frequency column in calculator**

The frequency (**FREQ**) column allow us to specify the number of repeats for each item.

**Steps**

- Press
**SHIFT**, followed by**MODE** - We should be at the following screen:

- Press ▼ (Down direction key) once
- We will get to the next set-up screen:

- Press
**4**to choose*4: STAT* - This is the
*Frequency*selection screen:

- Press
**1**to turn*Frequency*on

**Step 2: Entering Data**

Let's consider an example. (The full question can be found here.)

The following table shows the number of goals scored by the first twenty Manchester United players in the 2012/2013 title winning season.

Number of goals |
Frequency |

0 | 5 |

1 | 4 |

2 | 3 |

3 | 2 |

4 | 2 |

5 | 1 |

16 | 1 |

18 | 1 |

30 | 1 |

Now, we enter this data into the calculator.

**Step 2(a)**

- Press
**MODE** - We will get to the mode selection screen:

- Press
**2**to choose*2: STAT* - We will get:

- Press
**1**to choose*1: 1-VAR* - We will get:

However, if you get a screen without **FREQ** (as shown below), you need to enable the **Frequency column**. Go back to** Step 1**.

**Step 2(b): Entering X**

- Now we begin entering the data, starting from the first column X. For the example above, X is the number of goals scored.
- For the first entry, enter
**0**and press**=**

- Ignoring the FREQ column, we do the same for the subsequent rows:

- Fill up the remaining entries using the same approach.

**Step 2(c): Entering FREQ**

- Using the
**directional keys**, we navigate to first entry in the frequency column. - For the first entry, since 5 players scored 0 goal each, we enter
**5**on the row corresponding to 0 goal. - Next, 4 players scored 1 goal each, so we enter
**4**on the row corresponding to 1 goal.

Your screen should look like this:

Fill up for the remaining entries in the same manner. The table in your calculator should resemble the following table.

X |
FREQ |

0 | 5 |

1 | 4 |

2 | 3 |

3 | 2 |

4 | 2 |

5 | 1 |

16 | 1 |

18 | 1 |

30 | 1 |

**Step 2(d)**

- Press
**AC**to get back to the main screen

**Step 3: Calculating Mean and Standard Deviation**

**Step 3(a)**

- Press
**SHIFT**followed by**1** - We will get to the following screen:

- Press
**4**to select*4: Var* - We obtain the following screen:

**To obtain total number of samples or total frequency**:

- From step 3(a), press
**1**followed by**=**

**To obtain mean**:

- From step 3(a), press
**2**followed by**=**

**To obtain standard deviation**:

- From step 3(a), press
**3**followed by**=**

Once done, press **MODE** followed by **1** to switch back to normal operation.

**Practice Question & Closing Thoughts**

Here's another question for you to practice. (The full question can be found here.)

The following table shows the summarised score for a particular class in a Mathematics test.

Marks |
Mid-value |
Frequency |

1-10 | 5.5 | 5 |

11-20 | 15.5 | 10 |

21-30 | 25.5 | 5 |

31-40 | 35.5 | 18 |

41-50 | 45.5 | 2 |

Calculate the mean and standard deviation.

*Ans: Mean = 26, Standard Deviation = 11.8 (3 s.f.)*

At this point, I hope you are able to calculate both mean and standard deviation by your calculator.

Remember, use this method to *check your answer*! You still have to show workings in order *to score full marks*.

Let me know in the comments if you have questions or need instructions for other calculators!