Respuesta :
Answer:
[tex]0.51 - 1.96 \sqrt{\frac{0.51(1-0.51)}{557}}=0.468[/tex]
[tex]0.51 + 1.96 \sqrt{\frac{0.56(1-0.56)}{1507}}=0.552[/tex]
And the 95% confidence interval would be given (0.468;0.552).
Step-by-step explanation:
The estimated proportion of people who say that were underpaid is given by:
[tex]\hat p=\frac{284}{557}=0.510[/tex]
The confidence interval would be given by this formula
[tex]\hat p \pm z_{\alpha/2} \sqrt{\frac{\hat p(1-\hat p)}{n}}[/tex]
For the 95% confidence interval the value of [tex]\alpha=1-0.95=0.05[/tex] and [tex]\alpha/2=0.025[/tex], with that value we can find the quantile required for the interval in the normal standard distribution.
[tex]z_{\alpha/2}=1.96[/tex]
And replacing into the confidence interval formula we got:
[tex]0.51 - 1.96 \sqrt{\frac{0.51(1-0.51)}{557}}=0.468[/tex]
[tex]0.51 + 1.96 \sqrt{\frac{0.56(1-0.56)}{1507}}=0.552[/tex]
And the 95% confidence interval would be given (0.468;0.552).
