# CONFIDENCE

Formulas / CONFIDENCE
Calculate a range of values to estimate the population mean with a given confidence level.
`=CONFIDENCE(alpha, standard_dev, size)`
• alpha - required, a significance level
• standard_dev - required, the standard deviation of the population
• size - required, the sample size

## Examples

• `=CONFIDENCE(2, 3, 4)`

The CONFIDENCE function can be used to calculate a confidence interval for the population mean of travel to work. For example, this will return a confidence interval for the population mean of travel to work based on a sample size of 2, a confidence level of 3, and a standard deviation of 4.

• `=CONFIDENCE(15, 1, 8)`

The CONFIDENCE function can be used to calculate a confidence interval for the population mean of any parameter. For example, this will return a confidence interval for the population mean of any parameter based on a sample size of 15, a confidence level of 1, and a standard deviation of 8.

• `=CONFIDENCE(12, 2, 9)`

The CONFIDENCE function can be used to calculate a confidence interval for the population mean of any two parameters. For example, this example will return a confidence interval for the population mean of any two parameters based on a sample size of 12, a confidence level of 2, and a standard deviation of 9.

• `=CONFIDENCE(42, 3, 7)`

The CONFIDENCE function can be used to calculate a confidence interval for the population mean of any three parameters. This formula will return a confidence interval for the population mean of any three parameters based on a sample size of 42, a confidence level of 3, and a standard deviation of 7.

## Summary

The CONFIDENCE function is used to calculate a confidence interval for a population mean, which is the sample mean plus one standard deviation. It returns a #VALUE! error if any of the arguments are not numerical, and calculates the area under the standard normal curve to determine the confidence interval for a data set.

• The CONFIDENCE function has been improved and should be used instead of the previous version for increased accuracy.