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## Standard Deviation Formula

Standard Deviation is the technique to measure the “dispersement” in statistics.  This is a just optimum choice to calculate how much data is spread out. In brief, it will tell you how much data is spread out around the mean or average.  In the next step, you need to check either the scores are closest to the average or not? This is the form of normal distribution that is used commonly in statistics as a wonderful tool to understand the concept of standard deviation.

The graph has a wonderful deal to represent in the real-life too. The mean, mode, or average are frequently calculated in the mathematics. Each segment represents the one standard deviation from the mean. For example, 2σ means two standard deviations from the mean.

A normal distribution has the endless situations in real-life. Have you ever noticed any of such apps in your personal life too? If you are not sure then don’t panic, we had something interesting to explain to you. The standard deviation could also be given in the form of graphs as well. With the right knowledge and practice, you could always make predictions for the future behavior.

Further, it will also give you an idea of how well the data is clustered around the mean.  In case, if data is spread out well then data is quite away from the mean. If the bell curve is very steep then there would be only a small standard deviation from the graph.

#### Standard Deviation is of two types:

• Population Standard Deviation
• Sample Standard Deviation

$\large Population\;Standard\;Deviation= \sqrt{\frac{\sum_{i=1}^{n}\left(x-x_{i}\right)^{2}}{n}}$

$\large Sample\;Standard\;Deviation=\sqrt{\frac{\sum_{i=1}^{n}\left(x-x_{i}\right)^{2}}{n-1}}$

Where,
$\ x_{i} = Terms\;given\;in\;the\;data$
$\ \overline{x} = Mean$
N = Total number of Terms

### Relative Standard Deviation Formula

Relative Standard Deviation formula is used to calculate the standard error for a survey result. The number is multiplied by 100, so it can be expressed in percentage as well. The relative standard deviation necessarily represents the more information other than the standard error and gives you more statistical confidence.

$\large RSD=\frac{s\times 100}{\overline{x}}$

Where,
RSD = Relative standard deviation
s = Standard deviation
$\ \overline{x} = Mean\;of\;the\;data$

### Standard Form Formula

Looking at the equations standard form is extremely useful. In mathematics, every time the equation is a line, it simply means that you had two things that will vary. But most importantly, both of these things would have a consistent relationship.

At the first glance, this may be difficult identifying the relationship between the two. In fact, you may wonder whether the relationship is consistent or not. With Standard Form Formula, you could always clarify the relationship in the best possible way.

### Standard Error Formula

There is a close relation between standard deviation and the standard error. Both are used to measure the speed. The higher will be the number, the more evenly data is spread out. In simple words, two terms are essentially equal then why we have given two names here. Obviously, this is not the coincidence, there is one noticeable difference between the two. While the standard error statistics are used to sample data, standard deviation parameters are used for data population.

$\large SE_{\overline{x}}=\frac{S}{\sqrt{n}}$

Where,
s is the standard deviation
n is the number of observation

SO, what is the difference between statistic and parameter in mathematics? In statistics, you usually came across the terms standard error of mean and median. The expert mathematician can explain to you how far the sample statistics and actual population from each other. The large would be the size of a sample, small the standard error.