For each of the following, assume that the sample is a random sample from a distribution that is reasonably normally distributed and that we are doing inference for a population mean.

1. Find endpoints of at-distribution with 2.5% beyond them in each tail if the sample has sizen= 15.
2. Find endpoints of at-distribution with 10% beyond them in each tail if the sample has sizen= 5.
3. Find the area in at-distribution to the right of 2.6 if the sample has sizen= 16.
4. Find the area in at-distribution to the left of -2.7 if the sample has sizen= 35.