TTEST

The TTEST function returns the probability associated with a student’s t-test, based on the t-distribution function.

TTEST(sample-1-values, sample-2-values, tails, test-type)

sample-1-values: The collection containing the first set of sample number values.

sample-2-values: The collection containing the second collection of sample number values.

tails: A modal value specifying the number of tails to return.

one tail (1): Returns the value for a one-tailed distribution.

two tails (2): Returns the value for a two-tailed distribution.

test-type: A modal value specifying the type of t-test to perform.

paired (1): Perform a paired test.

two-sample equal (2): Perform a two-sample equal variance (homoscedastic) test.

two-sample unequal (3): Perform a two-sample unequal variance (heteroscedastic) test.

Examples

Suppose that cells B2 through G2 contain the values 57, 75, 66, 98, 92, and 80, respectively, and represent the sample-1-values. Suppose that cells B3 through G3 contain the values 87, 65, 45, 95, 88, and 79, respectively, and represent the sample-2-values. The various TTEST values for these two samples can be found with the formulas:

=TTEST(B2:G2, B3:G3, 1, 1) returns 0.418946725989974, for the one-tailed, paired test.

=TTEST(B2:G2 ,B3:G3, 2, 1) returns 0.837893451979947 for the two-tailed, paired test.

=TTEST(B2:G2, B3:G3, 1, 2) returns 0.440983897602811 for the one-tailed, two-sample equal test.

=TTEST(B2:G2, B3:G3, 2, 2) returns 0.881967795205622 for the two-tailed, two-sample equal test.

=TTEST(B2:G2, B3:G3, 1, 3) returns 0.441031763311189 for the one-tailed, two-sample unequal test.

See also
TDIST
TINV