A shoe store’s records show that 30% of the customers purchase by credit card. This morning 20 customers purchased shoes from the store. a. Find the probability that at least 12 of the customers used a credit card. b. What is the probability that at least 3 customers but not more than 6 used a credit card? c. What is the expected number of customers using a credit card?

A shoe store’s records show that 30% of the customers purchase by credit card. This morning 20 customers purchased shoes from the store. a. Find the probability that at least 12 of the customers used a credit card. b. What is the probability that at least 3 customers but not more than 6 used a credit card? c. What is the expected number of customers using a credit card?

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

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