What is 3 to the power of -4

Describe in detail how you would construct a 95% confidence interval for a set of 30 data points whose mean is 20 and population standard deviation is 3. be sure to show that you know the formula and how to plug into it. also, clearly state the margin of error.

How do i get my dad to stop making me gargle his pickle i want my mom to gargle my pickle not my dads

If you could answer these your a life saver