An important part of the customer service responsibilities of a telephone company relates to the speed with which troubles in residential services can be repaired. Suppose past data indicate that the likelihood is 0.70 that troubles in residential service can be repaired on the same day. For the first 5 troubles reported on a given day: What is the probability that all 5 will be repaired on the same day? What is the probability that at least 3 will be repaired on the same day? What is the probability that fewer than 2 will be repaired on the same day? The key components of this problem are: Sample size (trials) = 5 reported troubles Probability of success = 70% Number of successes: A: Exactly 5 B: 3 or more C: Fewer than two Solutions are: For A: BINOMDIST(5,5,0.7,FALSE) For B: (1-BINOMDIST(3,5,0.7,TRUE)) + BINOMDIST(3,5,0.7,FALSE) For C: BINOMDIST(2,5,0.7,TRUE) - BINOMDIST(2,5,0.7,FALSE) A student is taking a multiple-choice exam in which each question has 4 choices. Assuming that she has no knowledge of the correct answers to any of the questions, she has decided on a strategy in which she will place 4 balls (marked A, B, C and D) into a box. She randomly selects one ball for each question and replaces the ball in the box. The marking on the ball will determine her answer to the question. There are 5 multiple-choice questions on the exam. What is the probability that she will get 5 questions correct? What is the probability that she will get at least 4 questions correct? What is the probability that she will get no questions correct? What is the probability that she will get no more than 2 questions correct? The key components of this problem are: Sample size (trials) = 5 problems Probability of success = 25%
An important part of the customer service responsibilities of a telephone company relates to the speed with which troubles in residential services can be repaired. Suppose past data indicate that the likelihood is 0.70 that troubles in residential service can be repaired on the same day. For the first 5 troubles reported on a given day: What is the probability that all 5 will be repaired on the same day? What is the probability that at least 3 will be repaired on the same day? What is the probability that fewer than 2 will be repaired on the same day? The key components of this problem are: Sample size (trials) = 5 reported troubles Probability of success = 70% Number of successes: A: Exactly 5 B: 3 or more C: Fewer than two Solutions are: For A: BINOMDIST(5,5,0.7,FALSE) For B: (1-BINOMDIST(3,5,0.7,TRUE)) + BINOMDIST(3,5,0.7,FALSE) For C: BINOMDIST(2,5,0.7,TRUE) - BINOMDIST(2,5,0.7,FALSE) A student is taking a multiple-choice exam in which each question has 4 choices. Assuming that she has no knowledge of the correct answers to any of the questions, she has decided on a strategy in which she will place 4 balls (marked A, B, C and D) into a box. She randomly selects one ball for each question and replaces the ball in the box. The marking on the ball will determine her answer to the question. There are 5 multiple-choice questions on the exam. What is the probability that she will get 5 questions correct? What is the probability that she will get at least 4 questions correct? What is the probability that she will get no questions correct? What is the probability that she will get no more than 2 questions correct? The key components of this problem are: Sample size (trials) = 5 problems Probability of success = 25%