Which of the following statements accurately describes the difference between a one-samplettest and aztest?

1)

You must know the population variance (or standard deviation) for theztest but not for thettest.

2)

You must know the degrees of freedom to find the criticaltbut not the criticalzvalue.

3)

You must calculate the estimated variance (or standard deviation) for thettest but not for theztest.

4)

All of the above.