A news station would like to conduct an exit poll to determine the likelihood that a highly debated amendment will receive enough support to pass. The news station plans to construct a 90 percent confidence interval to estimate the proportion of voters supporting the amendment. Whatg expressions would give the smallest sample size that will result in a margin of error of no more than 3 percentage points?

The expression 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 .

The margin of error is of:

90% confidence level

So , z is the value of Z that has a p-value of , so .

What expression would give the smallest sample size that will result in a margin of error of no more than 3 percentage points?

We have to find n for which M = 0.03.

We have no prior estimate for the proportion, so we use . So

The expression is