There are three basic modes for the T-test. The first applies to a single wave and tests the hypothesis that the mean of the distribution is the specified value. In the second mode the test is used to compare the means of two waves. The third mode is used to compare

1. Testing a single wave

The wave data1 contains the following values: 19.2, 12.51, 19.05, 20.17, 19.87, 20.49,1 8.33, 22.87, 19.19, 15.55, 16.02, 20.04, 20.7, 19.5, 8, 24.1. To run the T-test execute the command:

`StatsTTest/T=1/Q /CI/Mean=20  data1`

The results are displayed in the T-Test table:

 n1 15 DF1 14 avg1 19.178 stdv1 2.83594 sxBar 0.732237 t_statistic -1.12259 critical 2.14479 CI_low 17.6075 CI_high 20.7485

Since the magnitude of the test statistic is smaller than the critical value, we can't reject H0: mean=20.

2. Testing two waves

In this example the two waves have different lengths. The test compares the means of the two distributions. To run the test execute:

`StatsTTest/T=1/Q /CI  data1,data2`

The results are displayed in the T-Test table:

 n1 15 DF1 14 avg1 19.178 stdv1 2.83594 n2 10 DF2 9 avg2 21.731 stdv2 2.45896 t_statistic -2.39024 P 0.0254172 DFc 21.281 lowCritical -2.07794 highCritical 2.07794 CI_1_Low 18.7725 CI_1_High 19.5835 CI_2_Low 21.1747 CI_2_High 22.2873 Accept 0

In this case the statistic is outside the critical values interval and so H0: the two waves have the same means, must be rejected.

3. Testing paired samples

The values in the wave data3 are: 14.61, 13.07, 17.92, 19.14, 17.72, 22.13, 19.98, 22.04, 21.2, 15.47, 13.08, 18.1, 19.61, 21.81, 21.81.

`StatsTTest/T=1/Q /CI/PAIR  data1,data3`

The results are displayed in the T-Test table:

 n 15 dBar 0.665334 sdBar 0.514836 tValue 1.29232 df 14 critical 2.14479 P 0.21717

In this example the statistic is smaller than the critical value and so we accept H0, i.e., there is no difference between the entries in data1 and data3. Forum Support Gallery