If you want to learn about the distinction between population and sample standard deviation, and why they're not calculated the same way, you should head to the lesson on sample variance and …

Range, variance, and standard deviation all measure the spread or variability of a data set in different ways. The range is easy to calculate—it's the difference between the largest and smallest data points …

If you want to learn about the distinction between population and sample standard deviation, and why they're not calculated the same way, you should head to the lesson on sample variance and …

You determine whether you are calculating the population variance or sample variance based on whether you have data for the entire population or just a sample of the population.

We'll go through a detailed example, starting from finding mid-points, calculating the mean, then the deviations from the mean, their squares, and the sum of their products with frequencies to find the …

We learn how to calculate the mean and standard deviation of a discrete random variable. The concept of a random variable is explained, along with methods to calculate its expected value (mean) and …

Let's actually calculate the population variance for this population right over here. Well, all we need to do is find the distance from each of these points to our mean right over here.

Range, variance, and standard deviation all measure the spread or variability of a data set in different ways. The range is easy to calculate—it's the difference between the largest and smallest data points …

Even when we subtract two random variables, we still add their variances; subtracting two variables increases the overall variability in the outcomes. We can find the standard deviation of the combined …

A standard deviation close to 0 indicates that the data points tend to be close to the mean (shown by the dotted line). The further the data points are from the mean, the greater the standard deviation.