How to write an algebraic expression for each worder phrase

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.

Based on the figures as marked, /\rqs = —

Find the area of the region that is inside r=3cos(theta) and outside r=2-cos(theta). sketch the curves.