# Difference between two means

Group A Mean = 43, STD DEV= 53, Count= 23

Group B Mean = 70, STD DEV= 27, Count = 6

I need to check if the Mean of B is greater than A.

1. Is it the formula below correct for my case?
2. Which is the value to find on the T-distribution table ?

$$t=\frac{(\bar{X}_1-\bar{X}_2)}{\sqrt{\frac{s_1^2}{n_1-1}+\frac{s_2^2}{n_2-1}}}$$

t = 2,380359393

• I edited the formula from your huge image into MathJax (verbatim); firstly it's a bit easier to read and secondly it makes it somewhat possible for blind people to have a suitable screen reader give them some sense of what's there. – Glen_b Nov 5 '16 at 11:16
• You did look up the t-distribution in wikipedia and should also look up the t-test itself in wikipedia: en.wikipedia.org/wiki/… this link will confirm the formula you asked for and will also show how to calculate the degrees of freedom d.f., which you will give you the correct row to look at the table you have linked to. The column to look at will depend on whether you plan to do a one-tailed test or a two-tailed test and whether p=0.05 is your cutoff or you choose a different cutoff. – Bernhard Nov 5 '16 at 12:08