# Manuals/calci/TTEST

TTEST(Array1,Array2,Tails,Type)

• and are the array of values.
• is the number of distribution tails.
• is the type of t-test.
• TTEST() returns the probability associated with a Students t-test.

## Description

• This function gives the probability of the t-test.
• It is also called student's t-test.
• This function is used to find the probability of two samples having the same mean but equal or unequal variances.
• In , and are two set of array values.
• ta is indicating the number of distribution tails. ta value is either 1 or 2.
• If Tails=1,then TTEST uses the one-tailed distribution.If Tails=2, then TTEST uses the two-tailed distribution. Type is the type of t-Test. Type value is 1 or 2 or 3.
 Type value t-Test is performed 1 Paired 2 Two-sample equal variance 3 Two-sample unequal variance
• Suppose we are giving ta and ty in decimals , then it will converted in to integers.
• TTEST uses the value of Array1 and Array2 to find non-negative t-statistic.
• If Tails=1, then it gives the probability of a higher value of the t-statistic with consideration of two arrays of samples with the same mean.
• If Tails=2, then TTEST is gives double that when ta=1 and corresponds to the probability of a higher absolute value of the t-statistic with the consideration of same mean.

This function will give the result as error when

```     1. Array1 and Array2 have a different number of data points and Type=1.
2. Any one of the argument is nonnumeric.
3. Tails>2 and Type>3.
```

## Examples

A B C D E F G
1 3 5 14 10 8 2 15
2 11 19 5 4 15 7 3
1. =TTEST(A1:G1,A2:G2,1,1)=0.399108571503
2. =TTEST(A1:G1,A2:G2,2,1)=0.7982171430076
3. =TTEST(A1:G1,A2:G2,1,2)=0.3725946027453
4. =TTEST(A1:G1,A2:G2,2,2)=0.7451892054907
5. =TTEST(A1:G1,A2:G2,1,3) = 0.37285157760157517
6. =TTEST(A1:G1,A2:G2,2,3) = 0.7457031552031503
7. =TTEST(A1:G1,A2:G2,2.2,1.3) = NAN

T-TEST