Standard Deviation Graph Explained. The more concentrated the smaller the standard deviation. Where xi value of the i th point in the data set.
Now we will have a chart like this. Excel is powerful tool to create graphs and visualise data and it can be used to create the bell graph. If needed you can change the chart axis and title.
Its symbol is σ the greek letter sigma the formula is easy.
The overall range of data is 9 1 8. In the second histogram the overall range is 7 3 4. The standard deviation of a probability distribution is the same as that of a random variable having that distribution. As explained above while s 2 is an unbiased estimator for the population variance s is still a biased estimator for the population standard deviation though markedly less biased than the uncorrected sample standard deviation.