Steps | Key Sequence | Screens |
1. Set up Stats Tests | STAT | |
twice | ||
ALPHA, then MATH (for 1–PropZInt...) | ||
2. Input number of successes, x | enter value for x, then ENTER | |
3. Input number of observations in SAMPLE, n | enter value for n, then ENTER | |
4. Input confidence level | enter confidence level (AS DECIMAL), then ENTER | |
5. Calculate confidence interval | ENTER | |
In this case, the 95% CI is from 0.49151 to 0.52235; is 0.5069 and n is 4040. |