# How to derive p-value from standard error between two group means?

Data was collected on binary variable and continuous variable. The binary variable represents two groups.

• Group 1 has a sample size $n_1$ and mean $\mu_1$ on the continuous variable
• Group 2 has a sample size $n_2$ and mean $\mu_2$ on the continuous variable

The significance test is as follows:

• H0: μ1 = μ2 versus Ha: μ1 > μ2, using an $\alpha$ significance level.

The first sample mean was $z$ pooled standard errors above the second sample mean.

• How can the p-value be derived from the standard error $z$?
• What if $n_1=15$, $n_2=30$, $\alpha=.10$ and $z=1.6$, what would the p-value be?
• This is probably homework or self-study. Please add the relevant tag. – Nick Sabbe Mar 29 '13 at 7:43
• I altered the question to try to make it general and useful for others who may read the question. – Jeromy Anglim Apr 28 '13 at 13:32