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Confidence Interval

In an election campaign, the party vying for an upset polls a sample of 100 voters. The party finds that 60 of 100 clearly express the intention of voting in favor of the party polling.

How many voters should be sampled if the party wants to estimate the population proportion with a sampling error of 5% or less? (Use confidence level of 95%)

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1. How many voters should be sampled if the party wants to estimate the population proportion with a sampling error of 5% or less? (Use confidence level of 95%)

I will use ^ for the squared sign. First, we need to determine the standard deviation of the voters' ratings (usually given or we would have to calculate from the raw data which is not provided here) to complete the equation to determine the final estimate and sample size. For now, then, we will use x = standard deviation (sigma represented by the symbol σ).

In this problem, the election campaign desires to ...

Solution Summary

Step-by-step computation of a confidence interval.

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