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

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In a particular retail clothing store, approximately 20% ofpotential customers who walk into the store make a purchase.
In a random sample of 20 customers that walked into thestore,
a. what is the probability that exactly 11 of the customers makepurchases? 0 Round to 3 significant digits.
b. what is the probability that at least 2 of the customers makepurchases? 0 Round to 3 significant digits.
c. how many of the customers are expected to make purchases? 0Round to 3 significant digits.
d. what is the standard deviation of the number of customers whomake purchases? 0 Round to 3 significant digits.