Step 1 :Given that the sample size (n) is 1018 and the sample proportion (p_hat) is 0.422.
Step 2 :The z-score for a 99% confidence level (Z_{α/2}) is approximately 2.576.
Step 3 :The margin of error (E) is calculated using the formula: \(E = Z_{α/2} * \sqrt{\frac{p_hat(1-p_hat)}{n}}\), which gives E = 0.026.
Step 4 :The confidence interval is then calculated using the formula: \(CI = p_hat ± E\).
Step 5 :Substituting the given values into the formula, we get the lower limit of the confidence interval as 0.396 and the upper limit as 0.448.
Step 6 :\(\boxed{[0.396, 0.448]}\) is the 99% confidence interval for the proportion of returned surveys.