# How do you use the 68 95 and 99.7 rule?

## How do you use the 68 95 and 99.7 rule?

The 7 Rule tells us that 68% of the weights should be within 1 standard deviation either side of the mean. 1 standard deviation above (given in the answer to question 2) is 72.

## Is standard deviation always 1?

The standard deviation of the z-scores is always 1. The graph of the z-score distribution always has the same shape as the original distribution of sample values. The sum of the squared z-scores is always equal to the number of z-score values.

## What's considered a low standard deviation?

A low standard deviation indicates that the values tend to be close to the mean (also called the expected value) of the set, while a high standard deviation indicates that the values are spread out over a wider range. ... It is algebraically simpler, though in practice less robust, than the average absolute deviation.

## Do you want a low standard deviation?

A low standard deviation means that the data is very closely related to the average, thus very reliable. A high standard deviation means that there is a large variance between the data and the statistical average, and is not as reliable.

## How do you trade standard deviation?

If prices trade in a narrow trading range, the standard deviation will return a low value that indicates low volatility. Conversely, if prices swing wildly up and down, then standard deviation returns a high value that indicates high volatility.

## Is volatility the standard deviation?

Volatility is a statistical measure of the dispersion of returns for a given security or market index. In most cases, the higher the volatility, the riskier the security. Volatility is often measured as either the standard deviation or variance between returns from that same security or market index.