Learning Materials
Features
Discover
Chapter 3: Q23E (page 171)
Investing in stocks. From a list of 15 preferred stocks recommended by your broker, you will select three to invest in. How many different ways can you select the three stocks from the 15 recommended stocks?
455
Over 30 million students worldwide already upgrade their learning with 91影视!
All the tools & learning materials you need for study success - in one app.
Get started for free
Male nannies. In a survey conducted by the International Nanny Association (INA) and reported on the INA Web site (www.nanny.org), 4,176 nannies were placed in a job in a given year. Only 24 of the nannies placed were men. Find the probability that a randomly selected nanny placed during the last year is a male nanny (a 鈥渕annie鈥�).
Evaluating the performance of quality inspectors. The performance of quality inspectors affects both the quality of outgoing products and the cost of the products. A product that passes inspection is assumed to meet quality standards; a product that fails inspection may be reworked, scrapped, or reinspected. Quality engineers at an electric company evaluated performances of inspectors in judging the quality of solder joints by comparing each inspector鈥檚 classifications of a set of 153 joints with the consensus evaluation of a panel of experts. The results for a particular inspector are shown in the table. One of the 153 solder joints was selected at random.
Committee鈥檚 judgment joint | Joint Acceptable | joint Rejectable |
Joint Acceptable | 101 | 10 |
joint Rejectable | 23 | 19 |
a. What is the probability that the inspector judged the joint to be acceptable? That the committee judged the joint to be acceptable?
b. What is the probability that both the inspector and the committee judged the joint to be acceptable? That neither judged the joint to be acceptable?
c. What is the probability that the inspector and the committee disagreed? Agreed?
Appeals of federal civil trials. The Journal of the American Law and Economics Association (Vol. 3, 2001) publishedthe results of a study of appeals of federal civil trials. Thefollowing table, extracted from the article, gives a breakdownof 2,143 civil cases that were appealed by either theplaintiff or the defendant. The outcome of the appeal, aswell as the type of trial (judge or jury), was determined foreach civil case. Suppose one of the 2,143 cases is selected
at random and both the outcome of the appeal and type of trial are observed.
Jury | Judge | Totals | |
Plaintiff trial win-reserved | 194 | 71 | 265 |
Plaintiff trial win-affirmed/dismissed | 429 | 240 | 669 |
Defendant trial win-reserved | 111 | 68 | 179 |
Defendant trial win- affirmed/dismissed | 731 | 678 | 1030 |
Total | 1465 | 678 | 2143 |
a. Find P (A), where A = {jury trial}.
b. Find P (B), where B = {plaintiff trial win is reversed}.
c. Are A and B mutually exclusive events?
d. Find
e. Find
f. Find
Study of why EMS workers leave the job. An investigation into why emergency medical service (EMS) workers leave the profession was published in the Journal of Allied Health (Fall 2011). The researchers surveyed a sample of 244 former EMS workers, of which 127 were fully compensated while on the job, 45 were partially compensated, and 72 had no compensated volunteer positions. EMS workers who left because of retirement were 7 for fully compensated workers, 11 for partially compensated workers, and 10 for no compensated volunteers. One of the 244 former EMS workers is selected at random.
a. Find the probability that the former EMS worker was fully compensated while on the job.
b. Find the probability that the former EMS worker was fully compensated while on the job and left due to retirement.
c. Find the probability that the former EMS worker was not fully compensated while on the job.
d. Find the probability that the former EMS worker was either fully compensated while on the job or left due to retirement.
3 Paying monthly bills online. Do most people pay their monthly bills online? ABA Bank Marketing and Sales (July-August 2015) reported that 37% of U.S. customers pay their bills online using a personal computer. The table lists the different methods by which customers pay their monthly bills and associated probabilities. Consider the following two events:
A = {Customer does not pay monthly bills online.}
B = {Customer does not pay monthly bills with a credit or debit card.}
Payment Method | Probability |
Online via personal computer | .37 |
Write check | .22 |
Checking account withdrawal | .10 |
Debit card | .09 |
Credit card | .07 |
Cash | .08 |
Mobile bill account | .04 |
Online via tablet or e-reader | .03 |
a. Find .
b. Find.
c. Find .
d. Use the additive law of probability to find .
What do you think about this solution?
We value your feedback to improve our textbook solutions.
Explanations 
Textbooks 
Flashcards 
91影视 AI 
Notes 
Study Plans 
Study Sets 
Find a degree 
Magazine