Confidence Interval Estimation
Use the data in Making Graphs by Hand practice problem.
1. Find the 95% confidence interval for estimating the percentage of students who watched TV for
2 hours or more on average each day using point estimate and margin of error.
_________ ± __________
2. What are the assumptions for using this confidence interval? Are the assumptions satisfied for
using this result?
3. Are you satisfied with the margin of error in this estimation, and why? If you wish to have a
margin of error within 4%, how large a sample do you need based on the data you have?
___________
4. Find the 95% confidence interval for estimating the average BMI using point estimate and
margin of error. (Find BMI calculation formula and compute BMI using the data.)
_________ ± __________
5. What are the assumptions for using this confidence interval? Are the assumptions satisfied for
using this result?
6. Are you satisfied with the margin of error in this estimation, and Why? If you wish to have a
margin of error within 1, how large a sample do you need based on the data you have?
___________