n=200, x=40, 95%confidence  Use the sample data and confidence level to construct the confidence interval estimate of the population proportion p.

1 Answer | Add Yours

embizze's profile pic

embizze | High School Teacher | (Level 1) Educator Emeritus

Posted on

A confidence of 95% implies that `alpha=.05,alpha/2=.025`



`z_(alpha/2)=1.96` from a table.

The interval we seek is given by:



`.2-1.96sqrt((.2(.8))/200)<p<.2+1.96sqrt((.2(.8))/200)`  or approximately:


Thus, with 95% confidence, we can say that 14.5%<p<25.5%


We’ve answered 317,364 questions. We can answer yours, too.

Ask a question