In a large university, 15% of the students are female. If a random sample of twenty students is selected, a.what is the probability that the sample

In a large university, 15% of the students are female. If a random sample of twenty students is selected,

a.what is the probability that the sample contains exactly four female students?

I believe the way to calculate this is:

P(3/20) females

3 f/2^20