Answer:
The 95% confidence interval is 
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.

In which
z is the z-score that has a p-value of
.
A random sample of 432 voters revealed that 100 are in favor of a certain bond issue.
This means that 
95% confidence level
So
, z is the value of Z that has a p-value of
, so
.
Confidence interval:


The 95% confidence interval is 