Answer:
The margin of error for their finding at the 90% level of confidence 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 interval , we have the following confidence interval of proportions.
In which
z is the zscore that has a pvalue of .
For this problem, we have that:
A sample of 270 students, so .
50% of students were in favor of the proposal, so .
We are working with a 90% confidence interval:
So , z is the value of Z that has a pvalue of , so Z = 1.645.
The margin of error for their finding at the 90% level of confidence is
The margin of error is [/tex]
So
The margin of error for their finding at the 90% level of confidence is .