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

Expert Answers
embizze eNotes educator| Certified Educator

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%