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
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.
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.)
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