# What is standard deviation math?

## What is standard deviation math?

The Standard Deviation is a measure of how spread out numbers are. Its symbol is σ (the greek letter sigma) The formula is easy: it is the square root of the Variance.

## Do you want a high or low variance?

Low variance is associated with lower risk and a lower return. High-variance stocks tend to be good for aggressive investors who are less risk-averse, while low-variance stocks tend to be good for conservative investors who have less risk tolerance. Variance is a measurement of the degree of risk in an investment.

## How do you do variance?

The Many Ways We Use Variance

1. We calculate variance by first calculating the mean of the data, then summing the square of the differences and dividing by the number of data points. ...
2. Once we calculate the sample variance, we often are interested in the population variance, thus calculate a confidence interval.

## How do I calculate variance?

How to Calculate Variance

1. Find the mean of the data set. Add all data values and divide by the sample size n.
2. Find the squared difference from the mean for each data value. Subtract the mean from each data value and square the result.
3. Find the sum of all the squared differences. ...
4. Calculate the variance.

## How do I find the difference between two numbers in Excel?

Calculate the difference between two numbers by inputting a formula in a new, blank cell. If A1 and B1 are both numeric values, you can use the "=A1-B1" formula. Your cells don't have to be in the same order as your formula. For example, you can also use the "=B1-A1" formula to calculate a different value.