Online College Courses for Credit

Confidence Interval for population proportion

Confidence Interval for population proportion

Author: Bob Kibler
See More

Try Our College Algebra Course. For FREE.

Sophia’s self-paced online courses are a great way to save time and money as you earn credits eligible for transfer to many different colleges and universities.*

Begin Free Trial
No credit card required

29 Sophia partners guarantee credit transfer.

312 Institutions have accepted or given pre-approval for credit transfer.

* The American Council on Education's College Credit Recommendation Service (ACE Credit®) has evaluated and recommended college credit for 27 of Sophia’s online courses. Many different colleges and universities consider ACE CREDIT recommendations in determining the applicability to their course and degree programs.


CI for proportion



Do I get it?

Answers to "Do I get it?"

The sample proportion is 0.18 (18 divided by 100)

The z-score is 1.64 (Remember that 5% off of both sides is removed)

The margin of error is 0.06

The confidence interval is (0.12,0.24)

The confidence interval means that:

We are 90% confidence that the actually proportion of houses that utilize the bulk trash pick up in a given month is between 0.12 and 0.24 (or 12-24%)