All the necessary values have been found to find the 95% confidence interval. We have Za/2 = 1.960, p = 0.325, and n = 160. Find the lower bound of the confidence interval, rounding the result to four decimal places. p- Za/2 p(1 p) p - E = n 0.325 - 0.325(1 - 0.325) 160 %3D Find the upper bound of the confidence interval, rounding the result to four decimal places. p+ Za/2 p + E p(1 - p) %3D 0.325 + 0.325(1 - 0.325) 160 Therefore, a 95% confidence interval for the proportion of items returned at the store in this city is to.