Solve the problem.
-Of 132 adults selected randomly from one town, 33 of them smoke. Construct a 99% confidence interval for the true percentage of all adults in the town that smoke.
A)16.2%

Question

Solve the problem.
-Of 132 adults selected randomly from one town, 33 of them smoke. Construct a 99% confidence interval for the true percentage of all adults in the town that smoke.
A)16.2% < p < 33.8%
B)18.8% < p < 31.2%
C)15.3% < p < 34.7%
D)17.6% < p < 32.4%

Quizplus · Accepted Answer

The confidence interval for a proportion is calculated using the formula: $$p \pm Z \sqrt{\frac{p(1-p)}{n}}$$, where $p$ is the sample proportion, $Z$ is the Z-score corresponding to the confidence level, and $n$ is the sample size. Here, $p = \frac{33}{132}$, $n = 132$, and for a 99% confidence level, $Z \approx 2.576$. Plugging these values into the formula gives the interval 15.3% to 34.7%.

Solve the Problem. -Of 132 Adults Selected Randomly from One Town, 33 of Town