Answer:
The answer is "(0.73,0.87)".
Step-by-step explanation:
Given:
number of girls[tex]= 64[/tex]
number of boys[tex]= 16[/tex]
Total number of children[tex]= 64+16= 80[/tex]
So,[tex]n=80[/tex]
Calculating the value of the proportion which is given by girls:
[tex]\hat{p}= \frac{\text{number of girls}}{\text{total number of childrens}}[/tex]
[tex]=\frac{64}{80}\\\\=\frac{8}{10}\\\\= 0.8[/tex]
Therefore the confidence interval is:
[tex]\to \hat{p}\pm z_{(1-\frac{\alpha }{2})}\sqrt{\frac{\hat{p}(1-\hat{p})}{n}}\\\\\to 0.8 \pm 1.75\sqrt{\frac{0.8(1-0.8)}{80}}\\\\\to 0.8 \pm 1.75 \sqrt{\frac{0.8(0.2)}{80}}\\\\\to 0.8 \pm 1.75 \sqrt{\frac{0.16}{80}}\\\\\to 0.8 \pm 1.75 \sqrt{0.002}\\\\\to 0.8 \pm 1.75 (0.04)\\\\\to 0.8 \pm 0.07\\\\\to (0.73,0.87)[/tex]
[tex]\therefore \\\\\text{The lower confidence limit} = 0.73\\\\\text{The upper confidence limit} = 0.87\\[/tex]
