Sample statistics | Normal CI | Student t-distribution CI | |||
sample size n | 30 | left area (percent) p | 0.025 | tc | 2.05 |
sample mean x̅ | 50 | right area p | 0.975 | margin of error E | 7.09 |
standard dev sx | 19 | lower limit pop mean | 43.2 | lower limit pop mean | 42.91 |
standard error of the mean | 3.47 | upper limit pop mean | 56.8 | upper limit pop mean | 57.09 |
confidence level | 0.95 | margin of error E | 6.80 | ||
Normal distribution: | 43.2 ≤ µ ≤ 56.8 | 50 ± 6.8 | |||
Student t-distribution: | 42.91 ≤ µ ≤ 57.09 | 50 ± 7.09 |