can someone explain standard deviation in english plz?

Answer 1

Standard deviation tells how far away a number in a set is from the mean. Like in data where the numbers are 2,4,6,8,10, the mean of this data is 6. So you have to find the difference of each number and the mean, then square each answer and add together(Sum of squared deviations). Divide this answer by the same number you divided the mean by - 1. So in this case you divided the the total of the numbers above by five, so divide the sum of squared deviation/5-1, this gives you the number they call the variance, take the square root of the answer, and you will get the standard deviation. So, the sum of the squares for this example is 40, by taking the the square root, you get 6.32

Answer 2

I'm assuming you have an understanding of an average (or 'mean').

If you have a collection of numbers, they have an average.

Some of the numbers in the collection will be closer to the average, some will be further away.

The standard deviation is a measure of 'how scattered the numbers are, compared to the average'.

For example, take the ages of children in a school year. Say the average is 12. Then all the children in the year are probably 11, 12 or 13 years old. So all the numbers are quite close to the average number (nobody is more than one year away from the average), so you have a low standard deviation.

On the other hand, take the ages of everyone in the town. You'll have a whole range of them from the very young to the very old, with an average somewhere in the middle. Some people will be close in age to the average age, some won't be, and the very young and very old people will be quite a way off. So the standard deviation will be larger, because there's more of a spread of answers.

Answer 3

Standard deviation is a measure to determine what is the deviation of the resuts from the mean. I.e. I will use three numbers, 1, 2 and 4. The mean of the numbers is 2.333333. The next step is to deduct each number from their mean. 1 will produce 1.333333333. 2 will produce 0.333333333. 4 will produce -1.666666667. The next step is to square each of the differences. The resulting squares will be, 1.777777778, 0.111111111 and 2.777777778, respectively. After squaring, the summation of the squares will be computed. Summation means to add. That means, the sum will be 4.666666667. The sum is then divided by the number of samples minus 1(n-1). In this case, there are three samples, each with magnitudes 1, 2 and 4. Therefore, n-1 = 2. 4.666666667/2 = 2.333333333. the answer is then square-rooted. Therefore the standard deviation is 1.527525232.


I could have shown it much better if i had presented it using a table. unfortunately tables can't be made here.

Answer 4

Hi. In any group of similar things such as people, tires, tomatoes, etc. there is an average of some characteristic. This can be the average height of 21 year old females, the diameter of an orange, the weight of a Lima bean - anything. There will be an average, a maximum, a minimum, etc. If you plot the characteristic and the distribution is random, the plot will look like a bell. This is called the 'bell curve'. Standard deviation is a value that will include a percentage of the bell curve centered in the middle. One standard deviation (called 'sigma') contains a certain percentage, two sigma will contain more of the total, 3 sigma will contain MOST of the total. The rest is just numbers. Hope this helps.

Answer 5

The standard deviation is a statistic that tells you how tightly all the various examples are clustered around the mean in a set of data. When the examples are pretty tightly bunched together and the bell-shaped curve is steep, the standard deviation is small. When the examples are spread apart and the bell curve is relatively flat, that tells you you have a relatively large standard deviation.

The standard deviation is one of several indices of variability that statisticians use to characterize the dispersion among the measures in a given population.

To calculate the standard deviation of a population it is first necessary to calculate that population's variance. Numerically, the standard deviation is the square root of the variance. Unlike the variance, which is a somewhat abstract measure of variability, the standard deviation can be readily conceptualized as a distance along the scale of measurement.

Answer 6

The standard deviation (SD) is a statistic that tells you how tightly all the various examples are clustered around the mean in a set of data. When the examples are pretty tightly bunched together and the bell-shaped curve is steep, the standard deviation is small. When the examples are spread apart and the bell curve is relatively flat, that tells you you have a relatively large standard deviation.

If the SD is large then the data is more likely be not trustworthy
if the SD is tight then the data is more likely to trustworthy

Answer 7

The standard deviation is a characteristic of the normal law.
To compute it, you need to calculate the average of the sample of the data, take the difference to this average for each value, square it, add all this numbers, divide by the number of data and square root the result.
The interest of this number is due to the characteristics of the normal law : 68% of the data should stand at +- 1 sd to the mean, 95% between +-2 sd, 99.7% between +-3sd

Answer 8

in probability and statistics, the standard deviation of a probability distribution, random variable, or population or multiset of values is defined as the square root of the variance.

The standard deviation is measured in the same units as the values of the population. For a population of distances in meters, the standard deviation is also measured in meters, whereas the variance is measured in square meters.

Answer 9

Standard Deviation

Click on the URL below for additional information concerning Standard Deviation,

en.wikipedia.org/wiki/Standard_deviation

- - - - - - -s-

Answer 10

hi kerry if u have some data and plt them and drew a line that is centered to the plotted data u will find that the average vertical distance between any point and the line is equal to the standard deviation