Answer
$0.27-0.087
Work Step by Step
$\hat{p}$ is the sample average of the boundaries, hence:$\hat{p}=\frac{(0.27-0.087)+(0.27+0.087)}{2}=0.27.$
E is half of the confidence interval, hence:$E=\frac{(0.27+0.087)+(0.27-0.087)}{2}=0.087$, hence the confidence interval: $0.27-0.087
