What percent is below 1 standard deviation?

What percent is below 1 standard deviation?

68%
Under this rule, 68% of the data falls within one standard deviation, 95% percent within two standard deviations, and 99.7% within three standard deviations from the mean.

What is considered a low standard deviation?

Low standard deviation means data are clustered around the mean, and high standard deviation indicates data are more spread out. A standard deviation close to zero indicates that data points are close to the mean, whereas a high or low standard deviation indicates data points are respectively above or below the mean.

Is standard deviation always less than 1?

In practice, the SD value should always be smaller than the mean. However, there is no statistical significance of the SD being greater than the mean: 1. If there are both negative and positive values in the distribution.

What is 1 standard deviation on a normal curve?

For an approximately normal data set, the values within one standard deviation of the mean account for about 68% of the set; while within two standard deviations account for about 95%; and within three standard deviations account for about 99.7%.

What does a standard deviation of 0.5 mean?

Example: Your score in a recent test was 0.5 standard deviations above the average, how many people scored lower than you did? Between 0 and 0.5 is 19.1% Less than 0 is 50% (left half of the curve)

Is low standard deviation good or bad?

Standard deviation helps determine market volatility or the spread of asset prices from their average price. When prices move wildly, standard deviation is high, meaning an investment will be risky. Low standard deviation means prices are calm, so investments come with low risk.

Can a standard deviation be negative?

The answer to this, is no. Conventionally when taking the square root we only take the positive value. The concept that a negative value appears come from a frequently omitted step and/or a not very known fact.

What does 1 standard deviation represent?

Specifically, if a set of data is normally (randomly, for our purposes) distributed about its mean, then about 2/3 of the data values will lie within 1 standard deviation of the mean value, and about 95/100 of the data values will lie within 2 standard deviations of the mean value. …

What is 1 standard deviation of the mean?

68% of the data is within 1 standard deviation (σ) of the mean (μ), 95% of the data is within 2 standard deviations (σ) of the mean (μ), and 99.7% of the data is within 3 standard deviations (σ) of the mean (μ).