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t test calculator

A t  test compares the means of two groups. For example, compare whether systolic blood pressure differs between a control and treated group, between men and women, or any other two groups.

Don't confuse t  tests with correlation and regression. The t test compares one variable (perhaps blood pressure) between two groups. Use correlation and regression to see how two variables (perhaps blood pressure and heart rate) vary together. Also don't confuse t  tests with ANOVA. The t  tests (and related nonparametric tests) compare exactly two groups. ANOVA (and related nonparametric tests) compare three or more groups. Finally, don't confuse a t test with analyses of a contingency table (Fishers or chi-square test). Use a t  test to compare a continuous variable (e.g., blood pressure, weight or enzyme activity). Use a contingency table to compare a categorical variable (e.g., pass vs. fail, viable vs. not viable).

1. Choose data entry format

Enter up to 50 rows.
Enter or paste up to 2000 rows.
Enter mean, SEM and N.
Enter mean, SD and N.
   Caution: Changing format will erase your data.

3. Choose a test

Unpaired t test.
Welch's unpaired t test (used rarely).
Paired t test.
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2. Enter data

Help me arrange the data.
Enter one value per row.

4. View the results