In a particular retail clothing store, approximately 25% of potential customers who walk into the store make a purchase. In a random sample of 20 customers that walked into the store,

a. what is the probability that exactly 8 of the customers make purchases?

Round to 3 significant digits.

b. what is the probability that at least 2 of the customers make purchases?

Round to 3 significant digits.

c. how many of the customers are expected to make purchases?

Round to 3 significant digits.