http://i.imgur.com/PXUDMPF.png 1. What are the independent variables and the dependent variables for the first table?

Is the dependent variable N and and independent variables the mean and standard deviation?

2. In the top table, do you want the means to be closer or farther apart? Can you tell me why?

You want them to be farther apart, because that means the drug is working. But isn't there less variability when they're closer together, which means less error.

3. What does standard deviation of 0 mean and how does this effect the within group variance and significance?

A SD of 0 means that all the numbers in that category are equal to the mean, I know that. I don't know how to explain how it effects the within group variance.

4. How is the bottom table different from a t-test?

T-test shows the standard error difference...that's as far as I got.