If Gallup has used an sis of size n=1021 and obtained the sample proportion p= 0.52 ,you can calculate that the margin of error for 95% confidence would be

To calculate the margin of error for a 95% confidence level with a sample size of n = 1021 and a sample proportion of p = 0.52, you need to use the formula for margin of error:

Margin of Error = Z * sqrt((p * (1 - p)) / n)

In this formula, Z represents the z-score for the desired confidence level, which for a 95% confidence level is approximately 1.96 (assuming a normal distribution).

Substituting the given values into the formula, we have:

Margin of Error = 1.96 * sqrt((0.52 * (1 - 0.52)) / 1021)

Let's now calculate this:

Margin of Error = 1.96 * sqrt((0.52 * 0.48) / 1021)
= 1.96 * sqrt(0.2496 / 1021)
= 1.96 * sqrt(0.0002444)
= 1.96 * 0.01562
≈ 0.030602

Therefore, the margin of error for a 95% confidence level would be approximately 0.0306 (or 3.06%) based on the given sample size and proportion.