Question

Use the given level of confidence and sample data to construct a confidence interval for the population proportion p.

Answer 1

Answer:

The 95% confidence interval for the population proportion is (0.778, 0.884).

Step-by-step explanation:

We have to calculate a 95% confidence interval for the proportion.

The sample proportion is p=0.831.

 

The standard error of the proportion is:

$\sigma_p=\sqrt{\dfrac{p(1-p)}{n}}=\sqrt{\dfrac{0.831*0.169}{195}}\\\\\\ \sigma_p=\sqrt{0.00072}=0.027$

The critical z-value for a 95% confidence interval is z=1.96.

The margin of error (MOE) can be calculated as:

$MOE=z\cdot \sigma_p=1.96 \cdot 0.027=0.053$

Then, the lower and upper bounds of the confidence interval are:

$LL=p-z \cdot \sisgma_p = 0.831-0.053=0.778\\\\UL=p+z \cdot \sisgma_p = 0.831+0.053=0.884$

The 95% confidence interval for the population proportion is (0.778, 0.884).