In a recent survey of 1002 people, 701 said that they voted in a recent presidential election. voting records show that 61% of eligible voters did not vote. how would the confidence interval change if we increased the confidence level to 99%? find the 99% confidence interval estimate to support your answer.

Respuesta :

The 99% confidence interval estimate of the proportion of people who say that they voted is (0.6623,0.7369).

Given sample size=1002 and confidence level of 99%.

In a sample with a number n of people surveyed with a probability of a success of π and a confidence level of 1-α, we have the following confidence interval of proportions.

π±z[tex]\sqrt{}[/tex]π(1-π)/n

in which z is the z score that has a p value of 1-α/2

n=1002,π=701/1002

So α=0.01, z is the value of Z that has a p value of 1-0.01/2=0.995, so Z=2.575.

Lower limit=π-[tex]z\sqrt{}[/tex]π(1-π)/n

=0.6996-2.575[tex]\sqrt{0.6996*0.3004/1002}[/tex]

=0.6623

Upper limit=π+[tex]z\sqrt{}[/tex]π(1-π)/n

= 0.6996+2.575[tex]\sqrt{0.6996*0.3004/1002}[/tex]

=0.7369

Hence the 99% confidence interval estimate of the proportion of people who say that they voted is (0.6623,0.7369).

Learn more about z test at https://brainly.com/question/14453510

#SPJ4