Step 1 :We want to estimate the true proportion of college students on our campus who voted in the 2012 presidential election with 95% confidence and a margin of error no greater than five percent.
Step 2 :We use the formula for sample size in a proportion estimation: \(n = \frac{{Z^2 \cdot p \cdot (1-p)}}{{E^2}}\), where \(Z\) is the Z-score for the desired confidence level, \(p\) is the estimated proportion, and \(E\) is the desired margin of error.
Step 3 :For a 95% confidence level, the Z-score is 1.96. We don't have an estimate for the proportion of students who voted, so we'll use 0.5 as a conservative estimate. The desired margin of error is 0.05.
Step 4 :Substituting these values into the formula, we get \(n = \frac{{(1.96)^2 \cdot 0.5 \cdot (1-0.5)}}{{(0.05)^2}}\).
Step 5 :Solving this equation, we find that we need to interview at least \(\boxed{385}\) students.