Problem
Express the confidence interval $28.2 \% \pm 5.7 \%$ in interval form. Express the answer in decimal format (do not enter as percents). Question Help: Video Post to forum
Solution
Step 1 ：The lower limit of the interval is calculated by subtracting the percentage error from the given percentage: \(28.2 \% - 5.7 \% = 22.5 \%\).
Step 2 ：The upper limit of the interval is calculated by adding the percentage error to the given percentage: \(28.2 \% + 5.7 \% = 33.9 \%\).
Step 3 ：To convert these percentages to decimal format, we divide by 100. So, the lower limit in decimal format is \(22.5 \% / 100 = 0.225\).
Step 4 ：Similarly, the upper limit in decimal format is \(33.9 \% / 100 = 0.339\).
Step 5 ：Final Answer: The confidence interval \(28.2 \% \pm 5.7 \%\), in interval form, is \(\boxed{[0.225, 0.339]}\).
