- A bank has had to repossess 100 homes. Fifty of these repossessed homes are expected to have market values that are less than the outstanding balance on the mortgage. An auditor randomly selects 10 different repossessed homes and records the number of homes which have market values less than the outstanding balance of the mortgage. What is the probability that all of the audited homes will have a market value less than the outstanding balance of the mortgage?
(Source: Unknown – 325HM?) - Worldwide golf ball sales total more than $1 billion annually. One reason for such a large number of golf ball purchases is that golfers lose them at a rate of 4.5 per 18-hole round (“Snapshots,” usatoday.com, January 29, 2004). What is the probability that
a. Zero balls will be lost in an 18-hole round?
b. Five or less balls will be lost in an 18-hole round?
c. Six or more balls will be lost in an 18-hole round?
(Source: LSKB, Fifth edition) - Historically, the probability that a library book will be returned at the university library in one week is .40. A random sample of 10 books is taken in one week.
a. What is the probability that 8 books will be returned?
b. Assuming this result is observed, what conclusion could the head librarian make about the accuracy of the historical rate of return?
(Source: Unknown – 327HM?)
- John Thurgood founded a company that translates Chinese books into English. His company is currently testing a computer-based translation service. Since Chinese symbols are difficult to translate, John assumes the computer program will make some errors, but then so do human translators. The computer error rate, as promised by the computer program developer, is no more than three errors per 400 words. Suppose John randomly selects a 1200-word passage. If 15 errors are found in the 1200-word passage, what would you conclude about the accuracy of the computer program developer’s claim? Why? (Assume that it is possible for the computer to make more than one error in translating each word in the passage).
(Source: Unknown – 224GSFS?)
Questions?