Question

A clinical trial test a method designed to increase the probability of conceiving a girl. in the study 510 babies were born in 255 of them were girls. use the sample data to construct a 99% confidence interval estimate of the percentage of girls born. based on the result does the method appear to be affected?

Answer 1

The confidence interval for a population proportion is given as:

`p=p^(\prime)\pm\mleft[Z_{((a)/(2))}\frac{\mleft(\mright?_{}p^(\prime)\mleft(1-p^(\prime)\mright)}{n}\mright]`

where:

p' = sample proportions = 0.5

n = sample size = 510

z = z score = 2.576

Hence, we have:

`\begin{gathered} p=0.5\pm\lbrack2.576*(0.5*0.5)/(510)\rbrack \\ p=0.50126\text{ or 0.49}874 \\ p=50.126\text{ \% or 49.874\%} \end{gathered}`