Student’s t-test

A one-sample (Student’s) t-test is used when we wish to test the value of the mean of a population, which we know can be modeled by the normal distribution, and we have to estimate the population variance from the sample.

When you formulate a test there are a number of fixed elements.

For the T-test these are:

-the null hypothesis μ =…

-the alternate hypothesis: left-sided, right-sided or two-sided (one-tailed or two-tailed)

-the significance level (alpha)

-the size of the sample

-the average of the observations

-the standard deviation of the observations

The distribution drawn is the distribution of the test statistic under the null hypothesis.

The value of the test statistic is plotted with a vertical line in the drawing. By typing or dragging the line you can adjust this.

There are a number of settings and buttons

p-value

In the diagram the area corresponding to the value of the test statistic obtained from the sample, or more extreme values, are colored red.

Critical region

In the distribution, the area where the null hypothesis test is rejected, is colored red.

Normal approximation

The best-fitting normal distribution is drawn.

Conclusion

With this option you obtain a detailed conclusion, the text of which can be exported as a RTF file, which almost all current text editors can read.