Standard deviation what is high or low

What is the standard deviation of just one number? What is the formula for the standard error? If IQ scores are normally distributed with a mean of and a standard deviation of 15, what Impact of this question views around the world. You can reuse this answer Creative Commons License.

A high standard deviation shows that the data is widely spread less reliable and a low standard deviation shows that the data are clustered closely around the mean more reliable. For example: A z-score of 1 is 1 standard deviation above the mean.

A z-score of 1. You can also just have z-scores on one side of the mean: 1 standard deviation below the mean is a z-score of -1 and a z-score of 2. A z-score of -3 is 3 standard deviations below the mean. The Empirical Rule states that For example, if you scored in the 85th percentile, you scored higher than 85 percent of test takers. To calculate the percentile, you will need to know your score, the mean and the standard deviation. Subtract the mean from your score. For example, if you scored 33 and the mean is 24, you would get a difference of 9.

Begin typing your search term above and press enter to search. Press ESC to cancel. Skip to content Home What does mean and standard deviation tell you in research?

Ben Davis June 1, What does mean and standard deviation tell you in research? How do you interpret standard deviation and variance? How do you explain standard deviation in words? How do you use standard deviation in a sentence? How does change in mean affect standard deviation? The biggest drawback of using standard deviation is that it can be impacted by outliers and extreme values.

Those interested in learning more about standard deviation and other financial topics may want to consider enrolling in one of the best investing courses currently available. Say we have the data points 5, 7, 3, and 7, which total You would then divide 22 by the number of data points, in this case, four—resulting in a mean of 5. The variance is determined by subtracting the mean's value from each data point, resulting in Each of those values is then squared, resulting in 0.

The square values are then added together, giving a total of 11, which is then divided by the value of N minus 1, which is 3, resulting in a variance of approximately 3. The square root of the variance is then calculated, which results in a standard deviation measure of approximately 1.

The average return over the five years was The value of each year's return less the mean is All those values are then squared to yield The variance is The square root of the variance is taken to obtain the standard deviation of Financial Analysis. Advanced Technical Analysis Concepts. Portfolio Management. Tools for Fundamental Analysis. Your Privacy Rights. To change or withdraw your consent choices for Investopedia. At any time, you can update your settings through the "EU Privacy" link at the bottom of any page.

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Asked 8 years, 11 months ago. Active 1 year ago. Viewed k times. The examples I've read so far have not said what makes it high or low.