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

question 106

Essay

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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Definitions:

Co-Sureties

Multiple parties who join together to provide surety or a guarantee for the performance or obligations of another.

Right of Contribution

The legal right of a party to reclaim a portion of damages or losses from another party who is jointly liable.

Surety's Obligation

A legal responsibility assumed by a surety, guaranteeing the performance or obligations of another party.

Debt

Money owed by one party to another under the condition of repayment.