It is known that 70% of the customers in a sporting goods store purchase a pair of running shoes. A random sample of 25 customers is selected. Assume that customers' purchases are made independently, and let x represent the number of customers who purchase running shoes.
a. What is the probability that exactly 18 customers purchase running shoes?
b. What is the probability that no more than 19 customers purchase running shoes?
c. What is the probability that at least 17 customers purchase running shoes?
d. What is the probability that between 17 and 21 customers, inclusively, purchase running shoes?

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The Answer of It is known that 70% of the customers in a sporting goods store purchase a pair of running shoes. A random sample of 25 customers is selected. Assume that customers' purchases are made independently, and let x represent the number of customers who purchase running shoes.
a. What is the probability that exactly 18 customers purchase running shoes?
b. What is the probability that no more than 19 customers purchase running shoes?
c. What is the probability that at least 17 customers purchase running shoes?
d. What is the probability that between 17 and 21 customers, inclusively, purchase running shoes?

It Is Known That 70% of the Customers in a Sporting