# ttest2

Hypothesis test for the means of two samples with unknown and equal standard deviations.

## Syntax

[h,pvalue,ci] = ttest2(x,y)

[h,pvalue,ci] = ttest2(x,y,name,value)

## Inputs

`x,y`- Data samples to be tested.
`name`- Name of an option whose value follows. Multiple name/value pairs are allowed. The supported options are alpha and dim.
`value`- Value for the preceeding option name.

## Outputs

- h
`0`if the null hypothesis is accepted.`1`if the null hypothesis is rejected.- pvalue
- The p-value of the test.
- ci
- A 100*(1-alpha)% confidence interval for the difference of the population means (x - y).

## Example

Simple ttest2 example.

```
x = [7.3 9.4 5.9 6.5 5.5 7 5.3 7.3 2.6 8.7 8.1 2.5 3.9 1.4 0.2 4 6 6.1 10.3 1.2];
y = [9.6 3.1 6 6.7 5.7 7.6 6.8 7 7.8 6.1 7.9 7 8.2 8.2 1.6 10 9.2 8.5 5.9 7.8];
[h,pvalue,ci] = ttest2(x,y)
```

```
h = 1
pvalue = 0.049394
ci = [Matrix] 1 x 2
-3.1456 -0.0043907
```

## Comments

ttest2 is an unpaired 2 sample t test and assumes that the samples comes from normally distributed populations. The null hypothesis is that the two population means are equal.