Q:

You are testing Ho: mu = 0 against Ha: mu (does not equal) 0 based on an SRS of 20 observations from a Normal population. What values of the t statistic are statistically significant at the alpha = 0.005 level?

Is the answer t > 2.861 or is it 3.174 > t > 2.539

or am I totally off on both tries?!

Thanks in advance!