Question: how to calculate the standard deviation with calculator?
Answer: First, work out the average, or arithmetic mean, of the numbers: Count: (How many numbers) ... 
Then, take each number, subtract the mean and square the result: Differences: -7.6, -1.6, 5.4, 4.4, -0.6. ... 
Now calculate the Variance: Sum of Differences2: 109.2. ... 
Lastly, take the square root of the Variance: Standard Deviation: