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You may have confused the requirements of the standard deviation (SD) formula for a difference between two distributions of sample means with that of a single distribution of a sample mean.

The formula we use for standard deviation depends on whether the data is being considered a population of its own, or the data is a sample representing a larger population.

The range is easy to calculate—it's the difference between the largest and smallest data points in a set. Standard deviation is the square root of the variance. Standard deviation is a measure …

The standard deviation formula may look confusing, but it will make sense after we break it down. In the coming sections, we'll walk through a step-by-step interactive example.

For example, the 34% for one standard deviation comes from the fact that the area under the normal curve within one standard deviation of the mean is symmetrically distributed around the …

The population standard deviation is a measure of how much variation there is among individual data points in a population. It's a way of quantifying how spread out the data is from its mean.

Practice Mean and standard deviation of a binomial random variable Get 3 of 4 questions to level up!

What is the average age of the bears at your zoo? What is the standard deviation? Round your answers to the nearest tenth.

To use the formula for standard deviation of p ^ , we need individual observations to be independent. When we are sampling without replacement, individual observations aren't …