Probability question

Question

Assume that a procedure yields a binomial distribution with a trial repeated n=20n=20 times. Find the probability of exactly x=11x=11 successes given the probability p=p=19/60 of success on a single trial.

(Report answer accurate to 4 decimal places.)

P(X)=

Answer 1

This is just an application of the binomial distribution formula:

P( x=11) = ₂₀C₁₁ (19/60)¹¹(41/60)⁹

where the C refers to the combination of 20 things 11 at a time.