Returns 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.
Array1 is the first data set.
Array2 is the second data set.
Tails specifies the number of distribution tails. If tails = 1, TTEST uses the one-tailed distribution. If tails = 2, TTEST uses the two-tailed distribution.
Type is the kind of t-Test to perform.
|If type equals
||This test is performed
||Two-sample equal variance (homoscedastic)
||Two-sample unequal variance (heteroscedastic)
- If array1 and array2 have a different number of data points, and type = 1 (paired), TTEST returns the #N/A error value.
- The tails and type arguments are truncated to integers.
- If tails or type is nonnumeric, TTEST returns the #VALUE! error value.
- If tails is any value other than 1 or 2, TTEST returns the #NUM! error value.
- TTEST uses the data in array1 and array2 to compute a non-negative t-statistic. If tails=1, TTEST returns the probability of a higher value of the t-statistic under the assumption that array1 and array2 are samples from populations with the same mean. The value returned by TTEST when tails=2 is double that returned when tails=1 and corresponds to the probability of a higher absolute value of the t-statistic under the “same population means” assumption.
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||Probability associated with a Student's paired t-Test, with a two-tailed distribution (0.196016)