Discuss the below:
Your company's internal auditor believes that 10% of the company's invoices contain errors. To check this theory, 20 invoices are randomly selected and 5 are found to have errors.
Q1: What is the probability that of the 20 invoices written, five or more would contain errors if the theory is valid?
a. .0433
b. .0319
c. .9567
d. .8660
Q2: An important part of the customer service responsibilities of a cable company relates to the speed with which trouble in service can be repaired. Historically, the data show that the likelihood is 0.75 that troubles in a residential service can be repaired on the same day. For the first five troubles reported on a given day, what is the probability that: Fewer than two troubles will be repaired on the same day?
a. .6328
b. .0010
c. .0156
d. .0146
Q3: A multiple-choice test has 30 questions and each one has five possible answers, of which one is correct. If all answers were guesses, find the probability of getting exactly four correct answers.
a. .0604
b. .1325
c. .2552
d. .8000