-14.1 ....standard deviation of 15......

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In summary, standard deviation is a measure of how spread out a set of data is from its mean value. It is calculated by finding the square root of the variance, which is the average of the squared differences from the mean. To calculate standard deviation, you first need to find the mean, then subtract the mean from each data point and square the result. The average of these squared differences is then found, and the square root of this average is the standard deviation. A standard deviation of -14.1 means that the data is tightly clustered around the mean and there is little variation. A negative standard deviation indicates that the data points are below the mean. A standard deviation of -14.1 is considered to be a very small amount of
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karush
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Given IQ scores are approximately normally distributed with a mean of 100 and standard deviation of 15,
the proportion of people with IQs above 130 is:
$ a.\ 95\% \quad b.\ 68\% \quad c.\ 5\% \quad d.\ 2.5\% \quad e.\ 12\%$

ok its been some moons since I looked at a standard deviation graph
so my choice would be by dice.
 
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It's not a "standard deviation graph", it's a normal distribution graph.

130 is two standard deviations above the mean. How much of the data will be within two standard deviations from the mean? So how much for each tail?
 
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=
 
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1. What is the meaning of a standard deviation of -14.1?

A standard deviation of -14.1 indicates that the data points are highly dispersed from the mean and are negatively skewed. This means that most of the data points are clustered towards the higher end of the data range, with few data points falling towards the lower end.

2. How is standard deviation calculated?

Standard deviation is calculated by taking the square root of the variance. The variance is calculated by finding the average of the squared differences between each data point and the mean.

3. What is the significance of a standard deviation of 15?

A standard deviation of 15 indicates the average amount of deviation of the data points from the mean. It provides a measure of how spread out the data is from the average.

4. Can a standard deviation be negative?

Yes, a standard deviation can be negative. This occurs when the data points are highly dispersed and negatively skewed, as mentioned in the first question.

5. How does standard deviation relate to the normal distribution?

In a normal distribution, approximately 68% of the data falls within one standard deviation of the mean, 95% within two standard deviations, and 99.7% within three standard deviations. Standard deviation is used to measure the spread of data in a normal distribution.

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