8.14 Margins of error
Interactive practice questions
Using the table provided, calculate the margin of error for a $90%$90% confidence interval for a sample of size $140$140 that has a sample proportion of $0.63$0.63. Give your answer to two decimal places.
| Standard Normal Probability | z-value |
|---|---|
| $0.9$0.9 | $1.282$1.282 |
| $0.925$0.925 | $1.440$1.440 |
| $0.95$0.95 | $1.645$1.645 |
| $0.975$0.975 | $1.960$1.960 |
| $0.99$0.99 | $2.326$2.326 |
| $0.995$0.995 | $2.576$2.576 |
Using the table provided, calculate the margin of error for an $80%$80% confidence interval for a sample of size $160$160 that has a sample proportion of $0.56$0.56. Give your answer to two decimal places.
Using the table provided, calculate the margin of error for a $95%$95% confidence interval for a sample of size $110$110 that has a sample proportion of $0.54$0.54. Give your answer to two decimal places.
Using the table provided, calculate the margin of error for a $99%$99% confidence interval for a sample of size $170$170 that has a sample proportion of $0.4$0.4. Give your answer to two decimal places.