## Definition

Returns the probability associated with t-test. Determines whether two samples are likely to have come from the same two underlying populations that have the same mean.

#### Sample Usage

`TTEST(A1:A4, B1:B4, 2, 1)`

#### Syntax

`TTEST(range1, range2, tails, type)`

• `range1` - The first sample of data or group of cells to consider for the t-test.

• `range2` - The second sample of data or group of cells to consider for the t-test.

• `tails` - Specifies the number of distribution tails.

• If `1`: uses a one-tailed distribution.

• If `2`: uses a two-tailed distribution.

• `type` - Specifies the type of t-Test.

• If `1`: a paired test is performed.

• If `2`: a two-sample equal variance (homoscedastic) test is performed.

• If `3`: a two-sample unequal variance (heteroscedastic) test is performed.

#### Notes

• `tails` and `type` must be numeric.

• `range1` and `range2` must have the same number of data points.

• `TTEST` uses the data in `range1` and `range2` to compute a non-negative test. If `tails` is set to `1``TTEST` returns the probability of a higher value of the t-statistic under the assumption that `range1` and `range2` are samples from populations with the same mean. The value returned by `TTEST` when `tails` is set to `2` is double that returned when`tails` is set to `1` and corresponds to the probability of a higher absolute value of the t-statistic under the "same population means" assumption.