Student T Test Chart. How to use this table this table contains critical values of the student s t distribution computed using the cumulative distribution function the t distribution is symmetric so that. Use this student s t distribution table to find t critical value given confidence level and degrees of freedom.
The t test compares one variable perhaps blood pressure between two groups. Prob t 50 t 75 t 80 t 85 t 90 t 95 t 975 t 99 t 995 t 999 t 9995 one tail 0 50 0 25 0 20 0 15 0 10 0 05 0 025 0 01 0 005 0 001 0 0005 two tails 1 00 0 50. A t test is the most commonly applied when the test statistic would follow a normal distribution if the value of a scaling term in the test statistic were known.
For example compare whether systolic blood pressure differs between a control and treated group between men and women or any other two groups.
Ttest a4 a24 b4 b24 1 1 the output will be 0 177639611. A marketing research firm tests the effectiveness of a new flavoring for a leading beverage using a sample of 21 people half of whom taste the beverage with the old flavoring and the other half who taste the beverage with the new flavoring. Student t value calculator effect size cohen s d for a student t test calculator p value calculator for a student t test t statistic and degrees of freedom calculator. In this formula t is the t value x 1 and x 2 are the means of the two groups being compared s 2 is the pooled standard error of the two groups and n 1 and n 2 are the number of observations in each of the groups.
