# CONFIDENCE.T function: Description, Usage, Syntax, Examples and Explanation

## What is CONFIDENCE.T function in Excel?

## Syntax of CONFIDENCE.T function

CONFIDENCE.T(alpha,standard_dev,size)

The CONFIDENCE.T function syntax has the following arguments:

- Alpha Required. The significance level used to compute the confidence level. The confidence level equals 100*(1 – alpha)%, or in other words, an alpha of 0.05 indicates a 95 percent confidence level.
- Standard_dev Required. The population standard deviation for the data range and is assumed to be known.
- Size Required. The sample size.

## CONFIDENCE.T formula explanation

- If any argument is nonnumeric, CONFIDENCE.T returns the #VALUE! error value.
- If alpha ≤ 0 or alpha ≥ 1, CONFIDENCE.T returns the #NUM! error value.
- If standard_dev ≤ 0, CONFIDENCE.T returns the #NUM! error value.
- If size is not an integer, it is truncated.
- If size equals 1, CONFIDENCE.T returns #DIV/0! error value.

## Example of CONFIDENCE.T function

Steps to follow:

1. Open a new Excel worksheet.

2. Copy data in the following table below and paste it in cell A1

Note: For formulas to show results, select them, press F2 key on your keyboard and then press Enter.

You can adjust the column widths to see all the data, if need be.

Formula |
Description |
Result |

=CONFIDENCE.T(0.05,1,50) | Confidence interval for the mean of a population based on a sample size of 50, with a 5% significance level and a standard deviation of 1. This is based on a Student’s t-distribution. | 0.2841968 |