Question

According to the U.S. Census Bureau, 42% of men who worked at home were college graduates. In a sample of 480 women who worked at home, 157 were college graduates. Part 1 out of 3 Find a point estimate for the proportion of college graduates among women who work at home. Round the answer to three decimal places. The point estimate for the proportion of college graduates among women who work at home is .

Answer 1

Answer:

1) $0.327 - 0.539 \sqrt{\frac{0.327(1-0.327)}{480}}=0.315$

The point estimate for the proportion of college graduates among women who work at home is 0.327

2) $0.327 - 0.539 \sqrt{\frac{0.327(1-0.327)}{480}}=0.315$

$0.327 + 0.539 \sqrt{\frac{0.327(1-0.327)}{480}}=0.339$

The 80% confidence interval is given by (0.315; 0.339)

Step-by-step explanation:

For this case we have the following info given:

$X = 157$ represent the women who worked at home who were college graduates

$n = 480$ the sample size selected

Part 1

In order to find the proportion of college graduates among women who work at home and we can use the following formula:

$\hat p=\frac{X}{n} = \frac{157}{480}= 0.327$

The point estimate for the proportion of college graduates among women who work at home is 0.327

Part 2

Construct an 80% confidence interval for the proportion of women who work at home who are college graduates. Round the answer to three decimal places. An 80% confidence interval for the proportion of women who work at home Is < p <

The confidence interval for the true proportion would be given by this formula

$\hat p \pm z_{\alpha/2} \sqrt{\frac{\hat p(1-\hat p)}{n}}$

For the 80% confidence interval the value for the significance is$\alpha=1-0.8=0.2$ and $\alpha/2=0.1$, the critical value would be given by:

$z_{\alpha/2}=0.539$

And replacing we goot:

$0.327 - 0.539 \sqrt{\frac{0.327(1-0.327)}{480}}=0.315$

$0.327 + 0.539 \sqrt{\frac{0.327(1-0.327)}{480}}=0.339$

The 80% confidence interval is given by (0.315; 0.339)