I am new to this and not quite sure what I am doing. I am hoping you will be able to help me with a few problems. I am not sure where to begin or what test to even use. Here is the problem:

Twelve measurements each of the the hydrogen content (in percent number of atoms) of gas collected from the eruption of two volcanoes yielded means of 41.2 and 45.8 respectively and standard deviations of 5.2 and 6.7 respectively. If the necessary conditions are met, what is the 90% confidence interval of difference in the population means?

Is there any way you can help me with this?

Thank you!

Also, I was wondering if there is a simple way of explaining the difference in the tests?