N of attempts. N is the fixed number of trials. Let us look at the next example on Shortcut to binomial expansion Example 2.
P is the probability of success on any given trial.
For help in using the calculator read the Frequently-Asked Questions or review the Sample Problems. To access all lessons in Chapter 7. Is the binomial coefficient hence the name of the distribution. Q the probability of failure for any individual trial also denoted as 1-p.