Question: The following information is available for two

> Decide whether a discrete or continuous random variable is the best model for each of the following variables: a. The time for a computer algorithm to assign an image to a category. b. The number of bytes used to store a file in a computer. c. The ozone

> Decide whether a discrete or continuous random variable is the best model for each of the following variables: a. The time until a projectile returns to earth. b. The number of times a transistor in a computer memory changes state in one operation. c. Th

> Decide whether a discrete or continuous random variable is the best model for each of the following variables: a. The number of cracks exceeding one-half inch in 10miles of an interstate highway. b. The weight of an injection-molded plastic part. c. The

> The following circuit operates if and only if there is a path of functional devices from left to right. Assume that devices fail independently and that the probability of failure of each device is as shown. What is the probability that the circuit does n

> A computer system uses passwords that contain exactly eight characters, and each character is one of 26 lowercase letters (a–z) or 26 uppercase letters (A–Z) or 10 integers (0–9). Let Ω denote the set of all possible passwords, and let A and B denote the

> Table 2.1 provides data on wafers categorized by location and contamination levels. Let A denote the event that contamination is low, and let B denote the event that the location is center. Are A and B independent? Why or why not? Data from Table 2.1:

> An integrated circuit contains 10 million logic gates (each can be a logical AND or OR circuit). Assume the probability of a gate failure is p and that the failures are independent. The integrated circuit fails to function if any gate fails. Determine th

> A Web ad can be designed fromfour different colors, three font types, five font sizes, three images, and five text phrases. A specific design is randomly generated by the Web server when you visit the site. Let A denote the event that the design color is

> Consider the hospital emergency room data in Example 2.6. Let A denote the event that a visit is to hospital 4, and let B denote the event that a visit results in LWBS (at any hospital). Are these events independent? Data from Example 2.6:

> The following circuit operates if and only if there is a path of functional devices from left to right. The probability that each device functions is as shown. Assume that the probability that a device is functional does not depend on whether or not othe

> The following circuit operates if and only if there is a path of functional devices from left to right. The probability that each device functions is as shown. Assume that the probability that a device is functional does not depend on whether or not othe

> A credit card contains 16 digits. It also contains the month and year of expiration. Suppose there are 1 million credit card holders with unique card numbers. A hacker randomly selects a 16-digit credit card number. a. What is the probability that it bel

> An e-mail filter is planned to separate valid e-mails from spam. The word free occurs in 60% of the spam messages and only 4% of the valid messages. Also, 20% of the messages are spam. Determine the following probabilities: a. The message contains free.

> A recreational equipment supplier finds that among orders that include tents, 40% also include sleeping mats. Only 5% of orders that do not include tents do include sleeping mats. Also, 20% of orders include tents. Determine the following probabilities:

> An encryption–decryption system consists of three elements: encode, transmit, and decode. A faulty encode occurs in 0.5% of the messages processed, transmission errors occur in 1% of the messages, and a decode error occurs in 0.1% of the messages. Assume

> Two Web colors are used for a site advertisement. If a site visitor arrives from an affiliate, the probabilities of the blue or green colors being used in the advertisement are 0.8 and 0.2, respectively. If the site visitor arrives from a search site, th

> Suppose that a patient is selected randomly from those described in Exercise 2.4.11. Let A denote the event that the patient is in group 1, and let B denote the event that there is no progression. Determine the following probabilities: a. P(B) b. P(B |

> Consider the hospital emergency room data in Example 2.6. Use Bayes’ theorem to calculate the probability that a person visits hospital 4 given they are LWBS. Data from Example 2.6:

> Software to detect fraud in consumer phone cards tracks the number of metropolitan areas where calls originate each day. It is found that 1% of the legitimate users originate calls from two or more metropolitan areas in a single day. However, 30% of frau

> The following two questions appear on an employee survey questionnaire. Each answer is chosen from the five-point scale 1 (never), 2, 3, 4, 5 (always). Is the corporation willing to listen to and fairly evaluate new ideas? How often are my coworkers impo

> An ammeter that displays three digits is used to measure current in milliamperes.

> In the final inspection of electronic power supplies, either units pass or three types of nonconformities might occur: functional, minor, or cosmetic. Three units are inspected.

> The number of hits (views) is recorded at a high-volume Web site in a day.

> Each of four transmitted bits is classified as either in error or not in error.

> A computer system uses passwords that contain exactly eight characters, and each character is 1 of the 26 lowercase letters (a–z) or 26 uppercase letters (A–Z) or 10 integers (0–9). Let Ω denote the set of all possible passwords, and let A and B denote t

> It is known that two defective cellular phones were erroneously sent to a shipping lot that now has a total of 75 phones. A sample of phones will be selected from the lot without replacement. a. If three phones are inspected, determine the probability th

> The article “Term Efficacy of Ribavirin Plus Interferon Alfa in the Treatment of Chronic Hepatitis C” [Gastroenterology (1996, Vol. 111(5), pp. 1307–1312)], considered the effect of two treatments and

> Consider the hospital emergency department data in Example 2.6. Let A denote the event that a visit is to hospital 1, and let B denote the event that a visit results in admittance to any hospital. Determine the number of persons in each of the following

> A Web ad can be designed from four different colors, three font types, five font sizes, three images, and five text phrases. How many different designs are possible?

> The following table summarizes 204 endothermic reactions involving sodium bicarbonate. Let A denote the event that a reaction’s final temperature is 271 K or less. Let B denote the event that the heat absorbed is below target. Determine

> The rise time of a reactor is measured in minutes (and fractions of minutes). Let the sample space be positive, real numbers. Define the events A and B as follows: A = {x | x < 72.5} and B = {x | x > 52.5}. Describe each of the following events: a. A′ b

> Samples of emissions from three suppliers are classified for conformance to air-quality specifications. The results from 100 samples are summarized as follows: Let A denote the event that a sample is from supplier 1, and let B denote the event that a sam

> In control replication, cells are replicated over a period of two days. Two control mechanisms have been identified—one positive and one negative. Suppose that a replication is observed in three cells. Let A denote the event that all cells are identified

> Disks of polycarbonate plastic from a supplier are analyzed for scratch and shock resistance. The results from 100 disks are summarized here: Let A denote the event that a disk has high shock resistance, and let B denote the event that a disk has high sc

> A new analytical method to detect pollutants in water is being tested. This new method of chemical analysis is important because, if adopted, it could be used to detect three different contaminants—organic pollutants, volatile solvents, and chlorinated c

> Suppose that P(A | B) = 0.7, P(A) = 0.5, and P(B) = 0.2. Determine P(B | A).

> The British government has stepped up its information campaign regarding foot-and-mouth disease bymailing brochures to farmers around the country. It is estimated that 99% of Scottish farmers who receive the brochure possess enough information to deal wi

> Customers are used to evaluate preliminary product designs. In the past, 95% of highly successful products received good reviews, 60% of moderately successful products received good reviews, and 10% of poor products received good reviews. In addition, 40

> Eight cavities in an injection-molding tool produce plastic connectors that fall into a common stream. A sample is chosen every several minutes. Assume that the samples are independent. a. What is the probability that five successive samples were all pro

> A player of a video game is confronted with a series of four opponents and an 80% probability of defeating each opponent. Assume that the results from opponents are independent (and that when the player is defeated by an opponent the game ends). a. What

> The probability that a lab specimen contains high levels of contamination is 0.10. Five samples are checked, and the samples are independent. a. What is the probability that none contain high levels of contamination? b. What is the probability that exact

> A test of a printed circuit board uses a random test pattern with an array of 10 bits and each is equally likely to be 0 or 1. Assume the bits are independent. a. What is the probability that all bits are 1s? b. What is the probability that all bits are

> Redundant array of inexpensive disks (RAID) is a technology that uses multiple hard drives to increase the speed of data transfer and provide instant data backup. Suppose that the probability of any hard drive failing in a day is 0.001 and the drive fail

> Disks of polycarbonate plastic from a supplier are analyzed for scratch and shock resistance. The results from 100 disks are summarized as follows: Let A denote the event that a disk has high shock resistance, and let B denote the event that a disk has h

> A batch of 500 containers of frozen orange juice contains 5 that are defective. Two are selected, at random, without replacement, from the batch. Let A and B denote the events that the first and second containers selected are defective, respectively. a.

> If P(A) = 0.2, P(B) = 0.2, and A and B are mutually exclusive, are they independent?

> If P(A | B) = 0.3, P(B) = 0.8, and P(A) = 0.3, are the events B and the complement of A independent?

> A steel plate contains 20 bolts. Assume that 5 bolts are not torqued to the proper limit. Four bolts are selected at random, without replacement, to be checked for torque. a. What is the probability that all 4 of the selected bolts are torqued to the pro

> Semiconductor lasers used in optical storage products require higher power levels forwrite operations than for read operations. High-power-level operations lower the useful life of the laser. Lasers in products used for backup of higher-speed magnetic di

> The following information is available for two samples selected from independent normally distributed populations: Population A: n1 = 25 S12 = 16 Population B: n2 = 25 S22 = 25 a. Which sample variance do you place in the numerator of FSTAT? b. What is

> Determine the upper-tail critical value of F in each of the following one-tail tests. a. α = 0.05, n1 = 16, n2 = 21 b. α = 0.01, n1 = 16, n2 = 21

> Determine the upper-tail critical values of F in each of the following two-tail tests. a. α = 0.10, n1 = 16, n2 = 21 b. α = 0.05, n1 = 16, n2 = 21 c. α = 0.01, n1 = 16, n2 = 21

> One of the most innovative advances in online fundraising during the past decade has been the rise of crowd-funding websites. While features differ from site to site, crowd-funding websites give people an opportunity to set up an online fundraising web p

> Does co-browsing have positive effects on the customer experience? Co-browsing refers to the ability to have a contact center agent and customer jointly navigate an online document or mobile application on a real-time basis through the web. A study of bu

> Under what conditions should you use the F test to examine possible differences in the variances of two independent populations?

> Under what conditions should you use the pooled-variance t test to examine possible differences in the means of two independent populations?

> What are some of the criteria used in the selection of a particular hypothesis-testing procedure?

> The file AirportRating contains the rating of large and medium size airports in the United States and Canada. Source: Data extracted from N. Trejos, “Portland, Indianapolis Top Airport Rankings, USA Today, December 16, 2016, p. 4B. For large and medium a

> A taxicab company has been receiving an increasing number of complaints concerning the delay time between when a call for a taxicab is received and when the passenger is picked up. The file TaxiDelays contains the delay times (in minutes) for two drivers

> We Are Social and Hootsuite reported that the typical American spends 2.02 hours (121 minutes) per day accessing the Internet through a mobile device. Source: Digital in 2017 Global Overview, available at bit.ly/2jXeS3F. You wonder if males and females s

> The annual NFL Super Bowl is the most widely watched sporting event in the United States each year. In recent years, there has been a great deal of interest in the ads that appear during the game. These ads vary in length with most lasting 30 seconds or

> What social media tools do marketers commonly use? A survey by Social Media Examiner of B2B marketers (marketers that focus primarily on attracting businesses) and B2C marketers (marketers that primarily target consumers) reported that 267 (81%) of B2B m

> A bank with a branch located in a commercial district of a city has the business objective of improving the process for serving customers during the noon-to-1 p.m. lunch period. To do so, the waiting time (defined as the number of minutes that elapses fr

> Accounting Today identified top accounting firms in 10 geographic regions across the United States. All 10 regions reported growth in 2016. The Southeast and Gulf Coast regions reported growths of 12.03% and 9.47%, respectively. A characteristic descript

> Is there a difference in the variance of the satisfaction rating of traditional cellphone providers who bill for service at the end of a month (often under a contract) and prepaid cellphone service providers who bill in advance without a contract? The fi

> In Problem 9.40, what is the statistical decision if you test the null hypothesis at the 0.01 level of significance? Problem 9.40: In a one-tail hypothesis test where you reject H0 only in the lower tail, what is the p-value if ZSTAT = +1.38?

> In Problem 10.43, assume that two samples are selected from independent normally distributed populations. a. At the 0.05 level of significance, is there evidence of a difference between σ12 and σ22? b. Suppose that you want to perform a one-tail test. At

> The following information is available for two samples selected from independent but very right-skewed populations: Population A: n1 = 16 S12 = 47.3 Population B: n2 = 13 S22 = 36.4 Should you use the F test to test the null hypothesis of equality of v

> In Problem 10.39, what is your statistical decision? Problem 10.39: The following information is available for two samples selected from independent normally distributed populations: Population A: n1 = 25 S12 = 161.9 Population B: n2 = 25 S22 = 133.7

> In Problems 10.38 and 10.39, what is the upper-tail critical value for F if the level of significance, α, is 0.05 and the alternative hypothesis is H1: σ12 ≠ σ22?

> In Problem 10.39, how many degrees of freedom are there in the numerator and denominator of the F test? Problem 10.39: The following information is available for two samples selected from independent normally distributed populations: Population A: n1 =

> The Society for Human Resource Management (SHRM) collaborated with Globoforce on a series of organizational surveys with the goal of identifying challenges that HR leaders face and what strategies help them conquer those challenges. A 2016 survey indicat

> The U.S. Department of Transportation requires tire manufacturers to provide tire performance information on the sidewall of a tire to better inform prospective customers as they make purchasing decisions. One very important measure of tire performance i

> Does Cable Video on Demand (VOD D4+) increase ad effectiveness? A 2015 VOD study compared general TV and VOD D4+ audiences after viewing a brand ad. Data were collected on whether the viewer indicated that the ad made them want to visit the brand website

> An online survey asked 1,004 adults “If purchasing a used car made certain upgrades or features more affordable, what would be your preferred luxury upgrade?” The results indicated that 9% of the males and 14% of the females answered window tinting. Sour

> Let n1 = 100, X1 = 45, n2 = 50, and X2 = 25. a. At the 0.01 level of significance, is there evidence of a significant difference between the two population proportions? b. Construct a 99% confidence interval estimate for the difference between the two po

> Let n1 = 100, X1 = 50, n2 = 100, and X2 = 30. a. At the 0.05 level of significance, is there evidence of a significant difference between the two population proportions? b. Construct a 95% confidence interval estimate for the difference between the two p

> In a one-tail hypothesis test where you reject H0 only in the lower tail, what is the p-value if ZSTAT = +1.38?

> The file Concrete1 contains the compressive strength, in thousands of pounds per square inch (psi), of 40 samples of concrete taken two and seven days after pouring. Source: Data extracted from O. Carrillo-Gamboa and R. F. Gunst, “Measurement- Error-Mode

> To assess the effectiveness of a cola video ad, a random sample of 38 individuals from a target audience was selected to participate in a copy test. Participants viewed two ads, one of which was the ad being tested. Participants then answered a series of

> Multiple myeloma, or blood plasma cancer, is characterized by increased blood vessel formulation (angiogenesis) in the bone marrow that is a predictive factor in survival. One treatment approach used for multiple myeloma is stem cell transplantation with

> How do the fares for airlines that directly compete compare? The file Airlines contains roundtrip fares for nonstop travel from Philadelphia to 10 different U.S. destinations on Southwest Airlines and American Airlines that a frequent flyer collected. So

> Does LTE network performance vary between providers? The file LTE contains the download speed (in Mbps) on LTE connections of AT&T and Verizon providers in 31 U.S. large metro markets. Source: Data extracted from State of Mobile Networks: USA, August 201

> How do the ratings of TV and Internet services compare? The file Telecom contains the rating of 10 different providers. Source: Data extracted from ACSI Telecommunication Report 2017, available at bit.ly/2syfcbA. a. At the 0.05 level of significance, is

> A survey of nonprofit organizations showed that online fundraising has increased in the past year. Based on a random sample of 133 nonprofits, the mean one-time gift donation resulting from email outreach in the past year was $87. Assume that the sample

> Nine experts rated two brands of coffee in a taste-testing experiment. A rating on a 7-point scale (1 = extremely unpleasing, 7 = extremely pleasing) is given for each of four characteristics: taste, aroma, richness, and acidity. The following data store

> Fifteen volunteers are recruited to participate in an experiment. A measurement is made (such as blood pressure) before each volunteer is asked to read a particularly upsetting passage from a book and after each volunteer reads the passage from the book.

> An experimental design for a paired t test has 20 pairs of identical twins. How many degrees of freedom are there in this t test?

> In Problem 9.38, what is your statistical decision if you test the null hypothesis at the 0.01 level of significance? Problem 9.38: In a one-tail hypothesis test where you reject H0 only in the lower tail, what is the p-value if ZSTAT = -1.38?

> Brand valuations are critical to CEOs, financial and marketing executives, security analysts, institutional investors, and others who depend on well-researched, reliable information needed for assessments, and comparisons in decision making. Millward Bro

> We Are Social and Hootsuite reported that the typical American spends 2.02 hours (121 minutes) per day accessing the Internet through a mobile device. Source: Digital in 2017 Global Overview, available at bit.ly/2jXeS3F. You wonder if males and females s

> Repeat Problem 10.14 (a), assuming that the population variances from developed and emerging countries are not equal. Compare these results with those of Problem 10.14 (a).

> As a member of the international strategic management team in your company, you are assigned the task of exploring potential foreign market entry. As part of your initial investigation, you want to know if there is a difference between developed markets

> Repeat Problem 10.12 (a), assuming that the population variances in the two branches are not equal. Compare these results with those of Problem 10.12 (a). Problem 10.12: A bank with a branch located in a commercial district of a city has the business ob

> A bank with a branch located in a commercial district of a city has the business objective of developing an improved process for serving customers during the noon-to-1 p.m. lunch period. Management decides to first study the waiting time in the current p

> The annual NFL Super Bowl is the most widely watched sporting event in the United States each year. In recent years, there has been a great deal of interest in the ads that appear during the game. These ads vary in length with most lasting 30 seconds or

> A marketing researcher wants to estimate the mean amount spent ($) on Amazon.com by Amazon Prime member shoppers. Suppose a random sample of 100 Amazon Prime member shoppers who recently made a purchase on Amazon.com yielded a mean of $1,500 and a standa

> Accounting Today identified the top accounting firms in 10 geographic regions across the United States. All 10 regions reported growth in 2016. The Southeast and Gulf Coast regions reported growth of 12.03% and 9.47%, respectively. A characteristic descr

> Is there a difference in the satisfaction rating of traditional cellphone providers who bill for service at the end of a month often under a contract and prepaid cellphone service providers who bill in advance without a contract? The file CellphoneProvid

> In a one-tail hypothesis test where you reject H0 only in the lower tail, what is the p-value if ZSTAT = -1.38?