How to Calculate Mean & Standard Deviation by Calculator (Sharp EL-W531 series)

These are the instructions to calculate mean & standard deviation by the Sharp EL-W531 series calculators.

I have tested this on the Sharp EL-W531S and SHARP EL-W531XM calculators.

Standard Deviation from The Calculator

Standard Deviation from The Calculator

For those taking GCE O Levels Mathematics, take note you have to still have to show proper workings to obtain full marks.

Use the calculator to check your answer!


Important Buttons

, and CHANGE button

, and CHANGE button

Take note of the rarely used buttons required.

  • The , (comma) button
  • The CHANGE button

They are above the right bracket ) button.


Clearing Memory

Always clear the memory before entering any values.

 

Steps

  • Press 2nd F followed by ALPHA
  • You will get the following screen:
Clear Memory Screen

Clear Memory Screen

 

  • Press 1 to select 1: MEMORY
  • You will get the following confirmation screen:
Confirmation Screen

Confirmation Screen

 

  • Press 0 to clear memory

Step 1: Select Statistics Mode

Steps

  • Press MODE
  • You will get the following selection screen:
Mode Selection Screen

Mode Selection Screen

 

  • Press 1 to select 1: STAT
  • You will get the following selection screen:
2nd Selection Screen

2nd Selection Screen

 

  • Press 0 to select 0: SD
  • You should get the following screen, which indicates that statistics mode is selected.

Step 2: Enter The Data

The following data will be used as an example. Feel free to follow along.

Mid-value Frequency
5.5 5
15.5 10
25.5 5
35.5 18
45.5 2
 

Step 2(a) - Enter the first row: 5.5, 5

  • (Clear the memory if you haven't already done so)
  • Press 5.5
  • Press , (comma)
  • Press 5
  • Press CHANGE
  • You will get the following screen:
First Row Entered

First Row Entered

If you do not get DATA SET=   1, you have to clear the memory and start again.

 

Step 2(b) - Enter the second row: 15.5, 10

  • Press 15.5
  • Press , (comma)
  • Press 10
  • Press CHANGE
  • You will get the following screen:
Second Row Entered

Second Row Entered

Step 2(c) - Enter the 3 remaining sets

  • Use the same method as described in steps 2(a) and 2(b).
  • If all goes well, you should get the following 3 screens:
Third Row Entered

Third Row Entered

Fourth Row Entered

Fourth Row Entered

Fifth Row Entered

Fifth Row Entered

Step 2(d) - Check the entries

Mid-value (X) Frequency (F)
5.5 5
15.5 10
25.5 5
35.5 18
45.5 2
  • Use the ▲ ▼ directional keys to check the entries. They should correspond to the table above.
  • If you do not get the any of the following 5 screens or have extra DATA SETs, clear the memory and start from step 2(a) again.

Step 2(e)

  • Press ON/C

Step 3: Obtain the mean and standard deviation

To obtain the mean:

  • Press ALPHA
  • Press 4
  • Press =
  • You will obtain the mean:
Mean

Mean

To obtain the standard deviation:

  • Press ALPHA
  • Press 6
  • Press =
  • You will obtain the standard deviation:
Standard Deviation

Standard Deviation

Once done, press MODE followed by 0 to go back to normal mode.


Practice Question and Closing Thoughts

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

Calculate the mean and standard deviation.

Ans: Mean = 4.65, Standard Deviation: 7.55 (3 s.f.)

 

For those taking O Levels, use the calculator to check your answer. You still have to apply the formulas and show workings in order to score full marks!