Verizon Wireless would like to estimate the proportion of households that use cell phones for their phone service without a land line. A random sample of 150 households was selected and 48 relied strictly on cell phones for their service. The approximate standard error of the proportion for this sample is _______.
A)0.0381
B)0.0419
C)0.0580
D)0.0225

Question

Quizplus · Accepted Answer

The standard error of the proportion is calculated using the formula $\sqrt{\frac{p(1-p)}{n}}$, where $p$ is the sample proportion and $n$ is the sample size. Here, $p = \frac{48}{150}$ and $n = 150$. Plugging these values into the formula gives $\sqrt{\frac{(48/150)(1-48/150)}{150}} \approx 0.0381$.

Verizon Wireless Would Like to Estimate the Proportion of Households