# User:Regina/MYDrafts3

## Contents

### Details

The Student's test is related to the t-distribution. Its density function is

where is the Gamma function and the parameter *degree of freedom*.

#### Paired Samples

If type=1, TTEST calculates the p-value for paired samples. It uses the differences of the pairs. So in this case the data X and Y should have the same count n.

TTEST returns

#### Unpaired Samples, Equal Variance

If type = 2, TTEST calculates the p-value of a comparison of means for independent samples from populations with equal variance. Besides

it uses the pooled variance

and

TTEST returns

#### Unpaired Samples, Unequal Variances

If type = 3, TTEST calculates the p-value of a comparison of means for independent samples from populations with not necessarily equal variances.

TTEST returns .

OpenOffice.org uses internally the regularized incomplete beta function to calculate the integral.

An empty element or an element of type *string* is ignored and in case paired samples its corresponding element in the other sample too. In contrast to other spreadsheet applications OpenOffice.org has no type *boolean* but treats *false* as 0 and *true* as 1.