Lesson goal: A list of numbers: Checking the standard deviation

Previous: A list of numbers: Plot the histogram (Part 3) | Home | Next: Introduction: Make a flashing animation

The standard deviation is a measure of how much a group of numbers that have a bell-shaped (or Gaussian, or normal distribution) vary around their average. It is defined as $$\sigma=\sqrt{\frac{1}{N-1}\Sigma (x_i-{\bar x})^2}$$ It tells us if the data has a Gaussian distribution, then 68% of the numbers should fall between the ${\bar x}-\sigma$ and ${\bar x}+\sigma$. Let's see if this holds for the data set we're using here.

Now you try. Fix the code to compute the average, standard deviation, and then to tally the results.

Type your code here:


See your results here: