# TTEST Function

The TTEST function is one of the statistical functions. It is used to return the probability associated with a Student's t-Test. Use TTEST to determine whether two samples are likely to have come from the same two underlying populations that have the same mean.

The TTEST function syntax is:

TTEST(array1, array2, tails, type)

where

array1 is the first range of numeric values.

array2 is the second range of numeric values.

tails is the number of distribution tails. If it is 1, the function uses the one-tailed distribution. If it is 2, the function uses the two-tailed distribution.

type is a numeric value that specifies the kind of t-Test to be performed. The value can be one of the following:

Numeric value | The kind of t-Test
1 | Paired
2 | Two-sample equal variance (homoscedastic)
3 | Two-sample unequal variance (heteroscedastic)

The values can be entered manually or included into the cell you make reference to.

To apply the TTEST function,

1. select the cell where you wish to display the result,
2. click the Insert function icon situated at the top toolbar,
   or right-click within a selected cell and select the Insert Function option from the menu,
   or click the icon situated at the formula bar,
3. select the Statistical function group from the list,
4. click the TTEST function,
5. enter the required arguments separating by commas or select a range of cells with the mouse,
6. press the Enter button.

The result will be displayed in the selected cell.