EXAMPLE 8.6 Margins of Error
CASE 8.2 In the Christmas tree market survey, the margin of error of a 95% confidence interval for any value of and is
The results for various values of are
| 0.05 | 0.019 | 0.60 | 0.043 |
| 0.10 | 0.026 | 0.70 | 0.040 |
| 0.20 | 0.035 | 0.80 | 0.035 |
| 0.30 | 0.040 | 0.90 | 0.026 |
| 0.40 | 0.043 | 0.95 | 0.019 |
| 0.50 | 0.044 |
The survey team judged these margins of error to be acceptable and used a sample size of 500 in their survey.