Question: Visit the home page of the Statistics

> The financial services call center in Problem 2.20 also monitors call duration, the amount of time spent speaking to customers on the phone. The file CallDuration contains the following data for time, in seconds, spent by agents talking to 50 customers:

> Call centers today play an important role in managing dayto- day business communications with customers. Call centers must be monitored with a comprehensive set of metrics so that businesses can better understand the overall performance of those centers.

> What do millennials around the world want in a job? A Deloitte survey of millennials on work-life challenges found that millennials are looking for stability in an uncertain world, with 65% of millennials preferring a permanent, full-time job rather than

> One operation of a mill is to cut pieces of steel into parts that will later be used as the frame for front seats in an automobile. The steel is cut with a diamond saw and requires the resulting parts to be within {0.005 inch of the length specified by t

> How do the average credit scores of people living in different American cities differ? The data in Credit Scores is an ordered array of the average credit scores of 2,570 American cities. Source: Data extracted from www.bizjournals.com/sanantonionews/20

> How much time do commuters living in or near cities spend commuting to work each week? The file Commuting Time contains the average weekly commuting time in 30 U.S. cities. Source: Data extracted from Office of the New York City Comptroller, “NYC Econom

> The file Utility contains the following data about the cost of electricity (in $) during July 2017 for a random sample of 50 one-bedroom apartments in a large city. 96 171 202 178 147 102 153 197 127 82 157 185 90 116 172 111 148 213 130 165 141 149 206

> The file NBACost contains the total cost ($) for four tickets purchased on the secondary market, two beers, two soft drinks, two hot dogs, and one parking space at each of the 30 National Basketball Association arenas during a recent season. These costs

> Data was collected on salaries of compliance specialists in corporate accounting firms. The salaries ranged from $61,000 to $261,000. a. If these salaries were grouped into six class intervals, indicate the class boundaries. b. What class interval width

> Planning and preparing for the unexpected, especially in response to a security incident, is one of the greatest challenges faced by information technology professionals today. An incident is described as any violation of policy, law, or unacceptable act

> Construct an ordered array, given the following data from a sample of midterm exam scores in marketing: 88 78 78 73 91 78 85

> Construct an ordered array, given the following data from a sample of n = 7 midterm exam scores in accounting: 68 94 63 75 71 88 64

> Do social recommendations increase ad effectiveness? A study of online video viewers compared viewers who arrived at an advertising video for a particular brand by following a social media recommendation link to viewers who arrived at the same video by w

> You plan to conduct a marketing experiment in which students are to taste one of two different brands of soft drink. Their task is to correctly identify the brand tasted. You select a random sample of 200 students and assume that the students have no abi

> A study of selected Kickstarter projects showed that overall a majority were successful, achieving their goal and raising, at a minimum, the targeted amounts. In an effort to identify project types that influence success, selected projects were subdivide

> A survey of 1,520 Americans adults asked “Do you feel Overloaded with too much information?” The results indicate that 23% of females feel information overload compared to 17% of males. The results are: a. Construct

> Timetric’s 2016 survey of insurance professionals explores the use of technology in the industry. The file Technologies contains the responses to the question that asked what technologies these professionals expected to be most used by

> This table represents the summer power-generating capacity by energy source in the United States as of July 2016. What conclusions can you reach about the source of energy in July 2016?

> In addition to the impact of Big Data, what disruptive technology capability do executives anticipate will have the greatest impact on their firm over the next decade? A survey of 50 Fortune 1000 executives revealed the following: What conclusions can

> The Consumer Financial Protection Bureau reports on consumer financial product and service complaint submissions by state, category, and company. The following table, stored in FinancialComplaints1 , represents complaints received from Louisiana consumer

> The following table, stored in Smartphone Sales , represents the annual market share of smartphones, by type, for the years 2011, 2012, 2013, 2014, and 2015. Source: Data extracted from www.gartner.com/newsroom/id/3215217. a. What conclusions can you r

> The following data represent the responses to two questions asked in a survey of 40 college students majoring in business: What is your gender? (M = male; F = female) and What is your major? (A = Accounting; C = Computer Information Systems; a. Tally t

> A categorical variable has three categories, with the following frequencies of occurrence: a. Compute the percentage of values in each category. b. What conclusions can you reach concerning the categories?

> Four different beverages are sold at a fast-food restaurant: soft drinks, tea, coffee, and bottled water. a. Explain why the type of beverage sold is an example of a categorical variable. b. Explain why the type of beverage is an example of a nominal-s

> A political pollster is conducting an analysis of sample results in order to make predictions on election night. Assuming a two-candidate election, if a specific candidate receives at least 55% of the vote in the sample, that candidate will be forecast a

> Social media provides an enormous amount of data about the activities and habits of people using social platforms like Facebook and Twitter. The belief is that mining that data provides a treasure trove for those who seek to quantify and predict future h

> Three professors examined awareness of four widely disseminated retirement rules among employees at the University of Utah. These rules provide simple answers to questions about retirement planning (R. N. Mayer, C. D. Zick, and M. Glaittle, “Public Aware

> Download and examine Zarca Interactive’s “Sample Survey for Associations/Sample Questions for Surveys for Associations,” available at bit.ly/2p5HlGO. a. Give an example of a categorical variable included in the survey. b. Give an example of a numerical v

> The American Community Survey (www.census.gov/acs) provides data every year about communities in the United States. Addresses are randomly selected and respondents are required to supply answers to a series of questions. a. Describe a variable for which

> A recent PwC survey of 1,379 CEOs from a wide range of industries representing a mix of company sizes from Asia, Europe, and the Americas indicated that CEOs are firmly convinced that it is harder to gain and retain people’s trust in an increasingly digi

> The Gallup organization releases the results of recent polls on its website, www.gallup.com. Visit this site and read an article of interest. a. Describe the population of interest. b. Describe the sample that was collected. c. Describe a parameter of in

> Results of a 2017 Computer Services, Inc. (CSI) survey of a sample of 163 bank executives reveal insights on banking priorities among financial institutions (goo.gl/mniYMM). As financial institutions begin planning for a new year, of utmost importance is

> Visit the official website for Microsoft Excel, products .office.com/excel or Minitab (www.minitab.com) or JMP (www .jmp.com). Review the features of the program you chose and then state the ways the program could be useful in statistical analysis.

> A survey indicates that the vast majority of college students own their own smartphones. What information would you want to know before you accepted the results of this survey?

> A hotel management company runs 10 hotels in a resort area. The hotels have a mix of pricing—some hotels have budget-priced rooms, some have moderate-priced rooms, and some have deluxe-priced rooms. Data are collected that indicate the number of rooms th

> The following data represent the responses (Y for yes and N for no) from a sample of 40 college students to the question “Do you currently own shares in any stocks?” N N Y N N Y N Y N Y N N Y N Y Y N N N Y N Y N N N N Y N N Y Y N N N Y N N Y N N a. Deter

> An amusement park company owns three hotels on an adjoining site. A guest relations manager wants to study the time it takes for shuttle buses to travel from each of the hotels to the amusement park entrance. Data were collected on a particular day that

> The amount of monthly data usage by a sample of 10 cellphone users (in MB) was: 0.4, 2.7MB, 5.6, 4.3, 11.4, 26.8, 1.6, 1,079, 8.3, 4.2 Are there any potential irregularities in the data?

> The cellphone brands owned by a sample of 20 respondents were: Apple, Samsung, Appel, Nokia, Blackberry, HTC, Apple, Samsung, HTC, LG, Blueberry, Samsung, Samsung, APPLE, Motorola, Apple, Samsun, Apple, Samsung a. Clean these data and identify any irregu

> Suppose that 10,000 customers in a retailer’s customer database are categorized by three customer types: 3,500 prospective buyers, 4,500 first time buyers, and 2,000 repeat (loyal) buyers. A sample of 1,000 customers is needed. a. What type of sampling s

> Pre-numbered sales invoices are kept in a sales journal. The invoices are numbered from 0001 to 5000. a. Beginning in row 16, column 01, and proceeding horizontally in a table of random numbers (Table E.1), select a simple random sample of 50 invoice num

> The registrar of a university with a population of N = 4,000 full-time students is asked by the president to conduct a survey to measure satisfaction with the quality of life on campus. The following table contains a breakdown of the 4,000 registered ful

> A population has four members (called A, B, C, and D). You would like to select a random sample of n = 2, which you decide to do in the following way: Flip a coin; if it is heads, the sample will be items A and B; if it is tails, the sample will be items

> You want to select a random sample of n = 1 from a population of three items (which are called A, B, and C). The rule for selecting the sample is as follows: Flip a coin; if it is heads, pick item A; if it is tails, flip the coin again; this time, if it

> For a study that consists of personal interviews with participants (rather than mail or phone surveys), explain why simple random sampling might be less practical than some other sampling methods.

> Given a population of N = 93, starting in row 29, column 01 of the table of random numbers (Table E.1), and reading across the row, select a sample of N = 15 a. without replacement. b. with replacement.

> A random sample of 50 households was selected for a phone (landline and cellphone) survey. The key question asked was, “Do you or any member of your household own an Apple product (iPhone, iPod, iPad, or Mac computer)?” Of the 50 respondents, 20 said yes

> For a population of N = 902, verify that by starting in row 05, column 01 of the table of random numbers (Table E.1), you need only six rows to select a sample of N = 60 without replacement.

> For a population containing N = 902 individuals, what code number would you assign for a. the first person on the list? b. the fortieth person on the list? c. the last person on the list?

> Transportation engineers and planners want to address the dynamic properties of travel behavior by describing in detail the driving characteristics of drivers over the course of a month. What type of data collection source do you think the transportation

> The director of market research at a large department store chain wanted to conduct a survey throughout a metropolitan area to determine the amount of time working women spend shopping for clothing in a typical month. a. Indicate the type of data the di

> If two students score a 90 on the same examination, what arguments could be used to show that the underlying variable—test score—is continuous?

> One of the variables most often included in surveys is income. Sometimes the question is phrased “What is your income (in thousands of dollars)?” In other surveys, the respondent is asked to “ Select the circle corresponding to your income level” and is

> Suppose the following information is collected from Robert Keeler on his application for a home mortgage loan at the Metro County Savings and Loan Association. a. Monthly payments: $2,227 b. Number of jobs in past 10 years: 1 c. Annual family income:

> For each of the following variables, determine whether the variable is categorical or numerical and determine its measurement scale. If the variable is numerical, determine whether the variable is discrete or continuous. a. Amount of money spent on clot

> Referring to the results from Problem 2.100 on page 86 concerning the weights of Boston and Vermont shingles, write a report that evaluates whether the weights of the pallets of the two types of shingles are what the company expects. Be sure to incorpora

> In a random sample of 64 people, 48 are classified as “successful.” a. Determine the sample proportion, p, of “successful” people. b. If the population proportion is 0.70, determine the standard error of the proportion.

> For each of the following variables, determine whether the variable is categorical or numerical and determine its measurement scale. If the variable is numerical, determine whether the variable is discrete or continuous. a. Name of Internet service prov

> The following information is collected from students upon exiting the campus bookstore during the first week of classes. a. Amount of time spent shopping in the bookstore b. Number of textbooks purchased c. Academic major d. Gender Classify each vari

> A/B testing allows businesses to test a new design or format for a web page to determine if the new web page is more effective than the current one. Web designers decide to create a new call-to-action button for a web page. Every visitor to the web page

> The file Currency contains the exchange rates of the Canadian dollar, the Japanese yen, and the English pound from 1980 to 2016, where the Canadian dollar, the Japanese yen, and the English pound are expressed in units per U.S. dollar. a. Construct time-

> The data stored in Drink represent the amount of soft drink in a sample of 50 consecutively filled 2-liter bottles. a. Construct a time-series plot for the amount of soft drink on the Y axis and the bottle number (going consecutively from 1 to 50) on the

> The file Natural Gas contains the U.S. monthly average commercial and residential price for natural gas in dollars per thousand cubic feet from January 2008 through December 2016. Source: Data extracted from “U.S. Natural Gas Prices,” bit.ly/2oZIQ5Z, acc

> The file Protein contains calorie and cholesterol information for popular protein foods (fresh red meats, poultry, and fish). Source: U.S. Department of Agriculture. a. Construct frequency and percentage distributions for the number of calories. b. Const

> What was the average price of a room at two-star, three-star, and four-star hotels around the world during 2016? The file Hotel Prices contains the average hotel room prices in Canadian dollars (about U.S. $0.75 as of December 2016) per night paid by Can

> Studies conducted by a manufacturer of Boston and Vermont asphalt shingles have shown product weight to be a major factor in customers’ perception of quality. Moreover, the weight represents the amount of raw materials being used and is therefore very im

> The file CEO2016 includes the total compensation (in $millions) for CEOs of 200 S&P 500 companies and the one-year total shareholder return in 2016. Source: Data extracted from bit.ly/1QqpEUZ. For total compensation: a. Construct a frequency distributi

> According to the National Survey of Student Engagement, the average student spends about 15 hours each week preparing for classes; preparation for classes includes homework, reading and any other assignments. Source: Data extracted from bit.ly/2qSNwNo.

> Given a normal distribution with m = 50 and s = 5, if you select a sample of n = 100, what is the probability that X is a. less than 47? b. between 47 and 49.5? c. above 51.1? d. There is a 35% chance that X is above what value?

> Given a normal distribution with m = 100 and s = 10, if you select a sample of n = 25, what is the probability that X is a. less than 95? b. between 95 and 97.5? c. above 102.2? d. There is a 65% chance that X is above what value?

> A runner sprints around a circular track of radius 100 m at a constant speed of 7 m/s. The runner’s friend is standing at a distance 200 m from the center of the track. How fast is the distance between the friends changing when the distance between them

> Find the absolute maximum and absolute minimum values of f on the given interval. f(a) — 5 + 54х — 2х', [0,4]

> Find the critical numbers of the function. f (x) = x2e-3x

> Find the critical numbers of the function. F (x) = x4/5 (x – 4)2

> Find the critical numbers of the function. h (p) = p - 1/p2 + 4

> Find the critical numbers of the function. h (t) = t3/4 - 2t 1/4

> Find the critical numbers of the function. g (y) = y - 1/y2 - y + 1

> (a). Sketch the graph of a function that has two local maxima, one local minimum, and no absolute minimum. (b). Sketch the graph of a function that has three local minima, two local maxima, and seven critical numbers.

> Find the critical numbers of the function. g (t) = |3t – 4|

> Find the critical numbers of the function. s (t) = 3t4 + 4t3 - 6t2

> For each of the numbers a, b, c, d, r, and s, state whether the function whose graph is shown has an absolute maximum or minimum, a local maximum or minimum, or neither a maximum nor a minimum. yA 0 a b c dr

> Two carts, A and B, are connected by a rope 39 ft long that passes over a pulley P (see the figure). The point Q is on the floor 12 ft directly beneath P and between the carts. Cart A is being pulled away from Q at a speed of 2 ft/s. How fast is cart B m

> If a snowball melts so that its surface area decreases at a rate of 1 cm2/min, find the rate at which the diameter decreases when the diameter is 10 cm. (a). What quantities are given in the problem? (b). What is the unknown? (c). Draw a picture of the s

> Sketch the graph of a function f that is continuous on [1, 5] and has the given properties. f has no local maximum or minimum, but 2 and 4 are critical numbers

> Sketch the graph of a function f that is continuous on [1, 5] and has the given properties. Absolute maximum at 5, absolute minimum at 2, local maximum at 3, local minima at 2 and 4

> (a). Find the intervals on which f is increasing or decreasing. (b). Find the local maximum and minimum values of f. (c). Find the intervals of concavity and the inflection points. f (x) = x2/x2 + 3

> Find the critical numbers of the function. f (x) = x3 + 6x2 - 15x

> Sketch the graph of a function f that is continuous on [1, 5] and has the given properties. Absolute minimum at 1, absolute maximum at 5, local maximum at 2, local minimum at 4

> (a). Sketch the graph of a function on [-1, 2] that has an absolute maximum but no local maximum. (b). Sketch the graph of a function on [-1, 2] that has a local maximum but no absolute maximum.

> (a). Sketch the graph of a function that has a local maximum at 2 and is differentiable at 2. (b). Sketch the graph of a function that has a local maximum at 2 and is continuous but not differentiable at 2. (c). Sketch the graph of a function that has a

> Let f (t) be the temperature at time where you live and suppose that at time t =3 you feel uncomfortably hot. How do you feel about the given data in each case? (а) f'(3) — 2, f"(3) — 4 (Б) f (3) — 2, f"(3) — —4 (c) f'(3) = -2, f"(3) = 4 (d) f'(3) =

> If z2 = x2 + y2, dx/dt = 2, and dy/dt = 3, find dz/dt when x = 5 and y = 12.

> If x2 + y2 = 25 and dy/dt = 6, find dx/dt when y = 4.

> Sketch the graph of a function f that is continuous on [1, 5] and has the given properties. Absolute minimum at 2, absolute maximum at 3, local minimum at 4

> C (x) = x1/3 (x + 4) (a). Find the intervals of increase or decrease. (b). Find the local maximum and minimum values. (c). Find the intervals of concavity and the inflection points. (d). Use the information from parts (a)–(c) to sketch the graph. Check

> Suppose y = √2x + 1, where x and y are functions of t. (a). If dx/dt = 3, find dy/dt when x = 4. (b). If dy/dt = 5, find dx/dt when x = 12.

> The radius of a sphere is increasing at a rate of 5 mm/s. How fast is the volume increasing when the diameter is 80 mm?

> A cylindrical tank with radius 5 m is being filled with water at a rate of 3 m3/min. How fast is the height of the water increasing?

> A plane flying horizontally at an altitude of 1 mi and a speed of 500 mi/h passes directly over a radar station. Find the rate at which the distance from the plane to the station is increasing when it is 2 mi away from the station. (a). What quantities a

> Two people start from the same point. One walks east at 3 mi/h and the other walks northeast at 2 mi/h. How fast is the distance between the people changing after 15 minutes?