Answer:
Each shows two lines that make up a system of equations. If the graphs of the equations intersect, then there is one solution that is true for both equations. If the graphs of the equations do not intersect (for example, if they are parallel), then there are no solutions that are true for both equations.
The confidence interval would be (0.122, 0.278).
We first find our z-score. We want a 95% confidence interval:
0.95/2 = 0.475
Looking this up in the z-table, (http://www.statisticshowto.com/tables/z-table/) we see the z-score is 1.96.
The formula we will use is:

In this problem, p = 20/100 = 0.2, and n=100: