Find the 95% confidence interval for the p when X = 60 and n = 500.
Press STAT, then RIGHT ARROW twice to TESTS. Press A to select A:1PropZInt.



Enter 60 for x:. ARROW DOWN once and enter 500 for n:. ARROW DOWN once again to CLEVEL:. Enter the confidence interval as the decimal .95. Then ARROW DOWN once more to Calculate and press ENTER. The results are shown below.


The final screen reports not only
the confidence interval of the proportion p as (0.09152,
0.14848) in interval notation, but also is
also given as 0.12.
This
can also be written as 0.09152
< p < 0.14848.