A simple random sample of 8 employees is selected from a large firm. For the 8 employees, the number of days each was absent during the past month was found to be 0, 2, 4, 2, 1, 7, 3, and 2,...
Student researchers wanted to see whether a persons reaction time is affected by the time of day. They had a computer program that would display a red circle. When it changed to yellow, the subjects...
Sketch the vector field F by drawing a diagram like Figure 5 or Figure 9. F(x, y) = 0.3 i - 0.4j
The random variable x represents the number of tickets a police officer writes out each shift. Determine whether the distribution is a probability distribution. If it is not a probability...
Researchers wanted to investigate the relationship between employment and accommodation capacity in the European travel and tourism industry. The file EuroTourism contains a sample of 27 European...
During the 2016 presidential campaign, an NBC News/Wall Street Journal poll conducted between December, 16, 2015, and January 13, 2016, showed that Marco Rubio would beat Hillary Clinton in the...
The concentration of a reactant is a random variable with probability density function a. What is the probability that the concentration is greater than 0.5? b. Find the mean concentration. c. Find...
Tom and Danny each pick uniformly random real numbers between 0 and 1. Find the expected value of the smaller number.
The Gibbs Hill Lighthouse. Southampton, Bermuda In operation since 1846, the Gibbs Hill Lighthouse stands 117 feet high on a hill 245 feet high, so its beam of light is 362 feet above sea level....
Suppose f(3) = 2, f '(3) = 1/2 , and f'(x) > 0 and f''(x), < 0 for all x. (a) Sketch a possible graph for f. (b) How many solutions does the equation f (x) = 0 have? Why? (c) Is it possible that...
A cricket chirps 14.5 times per second when it is 92F outside. Is this observation influential? Why?
In determining seasonal indexes for the months of the year, a statistician finds the total of the unadjusted seasonal indexes is 1180 instead of 12 100, or 1200. What correction must be made to...
An article in the Journal of Pharmaceuticals Sciences (1991, Vol. 80, pp. 971977) presented data on the observed mole fraction solubility of a solute at a constant temperature and the dispersion,...
Refer to the Baseball 2016 data, which report information on the 30 Major League Baseball teams for the 2016 season. a. At the .05 significance level, can we conclude that there is a difference in...
According to a 2016 report by Fannie Mae, 39% of 18-to 20-year-old students use credit cards for everyday purchases. Suppose a local bank believes that this share will increase over time because of...
Suppose that 20,000 women are recruited in each group in the actual study. How much power would the study have under the same assumptions just given? Cancer The effect of using postmenopausal...
Compare overall survival curves of the two groups, and obtain a p-value? Ophthalmology In Table 14.33, we present data from the RP clinical trial described in Example 14.30 (on page 813) concerning...
Recall Exercise 1.2.19, where researchers investigated whether rhesus monkeys have some ability to understand gestures made by humans. In one part of the study, they found that 31 of 40 monkeys...
The following data represent the seat capacity for major airlines on an annual basis: a. Construct a bar graph representing the seat capacity of the major airlines for the five airlines indicated. b....
The file HotelAway contains the average room price (in US$) paid by various nationalities while traveling abroad (away from their home country) in 2016: 124 101 115 126 114 112 138 85 138 96 130 116...
In a survey of 823 human resource professionals concerning challenges they faced in the workplace, 329 said that employee retention/turnover was an important challenge and 181 said that employee...
A person randomly selects one of the six envelopes shown below. Each envelope contains a check that the person gets to keep. Determine the persons expectation if the checks in the envelopes are as...
Identify the research question and state it as a conjecture. Drivers today have many more distractions to deal with than drivers of a century ago. Lets focus on new drivers aged 16 to 17. Do you...
A dean wants a random sample, without replacement, of 10 students from the first-year class. There are 423 students in the first-year class. Assign numbers consecutively to the students, use the...
David can buy a copier from Staples for $500 that prints, copies, and scans. He can either pay the total amount at the time of purchase, or he can agree to pay the store $50 down and $40 a month for...
In a survey of 2202 U.S. adults, 1167 think antibiotics are effective against viral infections. Let p be the population proportion for the situation. (a) Find point estimates of p and q, (b)...
Statistics Canadas National Housing Survey shows that, in 2013, median individual income was $27,600, 10% of individuals made more than $80,400, and the top 1% got more than $191,100. Why does...
In a study of racism, Nail, Harton, and Decker (2003) had participants read a scenario in which a police officer assaulted a motorist. Half the participants read about an African American officer who...
What test can be performed to compare the breast cancer incidence rate between the ¥ 30.0g group and the 0g group? Cancer A paper was recently published concerning the association between alcohol...
Th e poll also asked voters to report the amount of time that the respondent spent reading or learning about local politics over the last week. Th e poll finds that, on average, respondents have...
The book Using Designed Experiments to Shrink Health Care Costs [1997, ASQ Quality Press] presented a case study of an unreplicated 2 5 factorial design to investigate the effect of five factors on...
A test is being conducted to see if the proportion of cases that get settled out of court is different between the different counties in a state. Seven counties will be included and the data will...
The odds against a rock concert selling out are 2 : 9. Determine the probability the concert (a) Sells out. (d) Does not sell out.
Eighty-eight percent of U.S. civilian full-time employees have access to medical care benefits. You randomly select nine civilian full-time employees. Find the probability that the number of civilian...
The Sally Coffee Shop is considering closing one hour earlier in the evening through the week. Sally obtained the following data from a study taken last week of the number of customers between the...
a. What is the parameter in this scenario? b. What are two possible explanations for Janine getting 23 out of 30 left -handed short serves in bounds? c. Which of the two explanations from part (b) do...
What are the observational/experimental units? Researchers from the University of California, Berkeley wondered whether upper-class individuals behave more unethically than lower-class individuals....
Refer to the previous exercise about the association between prices and sizes of houses. Recall that the data file HousePrices contains data on prices ($) and sizes (in square feet) for a random...
Fernando works 40 hours per week and makes $8.50 per hour. (a) How much money can he expect to earn in 1 year (52 weeks)? (b) If he saves all the money he earns, how long will he have to work to save...
Researchers were commissioned by the Violence In Childrens Television Investigative Monitors (VICTIM) to study the frequency of depictions of violent acts in Saturday morning TV fare. They selected a...
For the histogram in Exercise 22, which is greater, the mean or the median? Explain your reasoning. 12 10 6. 2 6 10 14 18 22 26 30 34 4) 2.
The table below provides information about hours of sleep. a. Calculate statistical power for a one-tailed test (a = 0.05, or 5%) aimed at determining if those in the sample sleep fewer hours, on...
Researchers Vogel et al. (JAMA, 2006) reported the following findings about the Study of Tamoxifen and Raloxifene (STAR), a study involving postmenopausal women who were at an increased risk for...
The computer output below shows a multiple regression model to predict grade point average (GPA) using six variables from the dataset SleepStudy. Gender is coded 0 for females and 1 for males;...
Assume that you are blind-folded and throw a dart at the dart board shown below. Assume that your dart sticks in the dart board, and not on a line. (a) Determine the probabilities that the dart lands...
Kwame borrowed $2500 for 5 months from a bank using a 3% discount note. (a) How much interest did Kwame pay the bank for the use of its money? (b) How much did he receive from the bank? (c) What was...
Find all intervals where each product will at least break even. The cost to produce x units of baseball caps is C = 100x + 6000, while the revenue is R = 500x.
Thirty-six percent of likely U.S. voters think that the federal government should get more involved in fighting local crime. You randomly select five likely U.S. voters and ask them whether they...
The following table shown in the file TextbookCosts shows the breakdown of the costs of a typical college textbook. a. Using the categories of publisher, bookstore, and author, construct a bar chart,...
A stemplot of the same cookies summarized in Exercise 1 is created, and the first row of that stemplot is 1 | 99. Identify the values represented by that row of the stemplot. Data from Exercise 1...
The owner of Maumee Motors wants to study the relationship between the age of a car and its selling price. Listed below is a random sample of 12 used cars sold at Maumee Motors last year: a. If we...
Perform the test in Problem 8.150, and report a twotailed p-value? Diabetes The insulin pump is a device that delivers insulin to a diabetic patient at regular intervals. It presumably regulates...
Eighty-five percent of Americans favor spending government money to develop alternative sources of fuel for automobiles. For a random sample of 120 Americans, find the mean, variance, and standard...
The expected sum of two fair dice is 7, the variance is 35/6. Let X be the sum after rolling n pairs of dice. Use Chebyshevs inequality to find z such that P(|X 7n| < z) 0.95. In 10,000 rolls of...
How much of an effect does your roommate have on your grades? In particular, does it matter whether your roommate brings a videogame to college? A study examining this question looked at n = 210...
Verify that the Divergence Theorem is true for the vector field F on the region E. F(x, y, z) = y 2 z 3 i + 2yz j + 4z - k, E is the solid enclosed by the paraboloid z = x 2 + y 2 and the plane z = 9
The depths (in inches) at which 10 artifacts are found are listed. 20.7 24.8 30.5 26.2 36.0 34.3 30.3 29.5 27.0 38.5 (a) Find the range of the data set. (b) Change 38.5 to 60.5 and find the range of...
A bank has two types of branches. A satellite branch employs 3 people, requires $400,000 to construct and open, and generates an average daily revenue of $10,000. A full-service branch employs 6...
Select the appropriate measure of central tendency for each scenario: a. A researcher obtains a sample of men who have been married for seven years and asks them to rate their levels of marital...
The voltage V, in volts, produced by an ac generator at time t, in seconds, is V(t) = 220 sin(120t) (a) What is the amplitude? What is the period? (b) Graph V over two periods, beginning at t = 0....
The city of Bradenton is offering simple interest loans to start-up businesses at a rate of 3.5%. Mr. Cannata obtains one of these loans of $6000 for 3 years to help pay for start-up costs of his...
An essential function in statistics and the study of the normal distribution is the error function a. Compute the derivative of erf (x). b. Expand e -t2 in a Maclaurin series; then integrate to find...
Seventy-six percent of stay-at-home mothers have a college degree or higher. You randomly select five stay-at-home mothers and ask them whether they have a college degree or higher. The random...
A physical therapist suggests that soft tissue massage therapy helps to reduce the numbers of days per week patients suffer from headaches. The table shows the numbers of days per week 18 patients...
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....
Referring to Problem 14.77, suppose that in addition to using ERA to predict the number of wins, the analytics specialist wants to include the league (0 = American, 1 = National) as an independent...
A firm employing 100 workers has an average absenteeism rate of 4%. On a given day, what is the probability of (a) no workers, (b) one worker, (c) more than six workers being absent?
Suppose a woman has 300 intermediate cells by age 45. What is the probability that she develops breast cancer by age 46? By age 50? Cancer The two-stage model of carcinogenesis is based on the...
Refer back to the previous exercise. Recall that the data file TVLife provides information on life expectancy and number of televisions per thousand people in a sample of 22 countries, as reported by...
An article in Oikos: A Journal of Ecology [Regulation of Root Vole Population Dynamics by Food Supply and Predation: A Two-Factor Experiment (2005, Vol. 109, pp. 387395)] investigated how food supply...
Consider the loglinear model with symbol (XZ, YZ). a. For fixed k, show that { ijk } equal the fitted values for testing independence between X and Y within level k of Z. b. Show that the Pearson and...
Suppose you want to travel D miles at a constant speed of (60 + x) mi/hr, where x could be positive or negative. The time in minutes required to travel D miles is T(x) = 60D(60 + x) -1 . Use the...
Use geometry to find the displacement of an object moving along a line for the time intervals (i) 0 t 5. (ii) 3 t 7. (iii) 0 t 8, where the graph of its velocity v = g(t) is given in the...
Find the work done by the force field F in moving an object from P to Q. F(x, y) = x 3 i + y 3 j; P(1, 0), Q(2, 2)
The amount of a certain radioactive material, in grams, present after t days is modeled by A(t) = 600e -0.05t . (a) Find the amount present after 12 days, to the nearest tenth of a gram. (b) Find the...
A survey of U.S. adults found that 75% support labeling legislation for genetically modified organisms (GMOs). You randomly select 20 U.S. adults and ask them whether they support labeling...
The closing price of Walmart stock at the end of its fiscal year (end of January) for five years is given in the following table. The CPI for January of each year is also provided. Deflate the stock...
Your roommate is reading Fantasyland: A Season on Baseballs Lunatic Fringe (Walker, 2006) and is intrigued by the statistical methods used by competitors in fantasy baseball leagues (in which...
Example 17 discussed EU carbon dioxide emissions, which had a mean of 7.9 and standard deviation of 3.6. a. Finlands observation was 11.5. Find its z-score and interpret. b. Swedens observation was...
Consider the data from the first replicate of Exercise 14-15, assuming that four blocks are required. Confound ABD and ABC (and consequently CD) with blocks. (a) Construct a design with four blocks...
Analysis of variance is used when comparing the means of ____ or more groups.
Team batting averages for major league baseball in 2015 are represented below. Find the variance and standard deviation for each league. Compare the results. NL AL 0.242-0.246 3 0.244-0.249 3...
Testing to see if there is evidence that the proportion of people who smoke is greater for males than for females. A situation is described for a statistical test. In each case, define the relevant...
Pick any number, multiply the number by 3, add 6 to the product, divide the sum by 3, and subtract 2 from the quotient. (a) What is the relationship between the number you started with and the final...
A bean bag is randomly thrown onto the square table top shown below and does not touch a line. Determine the probability that the bean bag lands on An area that is not green.
A taste test is given to 60 customers at a supermarket. The customers are asked to taste 4 types of cheese and to list their favorite. The results are summarized below. Network . . . . . . . . Number...
Consider a map of the contiguous United States. Imagine a graph with 48 vertices in which each vertex represents one of the contiguous states. Each edge would represent a common border between...
(a) Determine each hotels modified quota using the divisor 28. (b) Determine each hotels apportionment using Adams method. When appropriate round quotas to the nearest hundredth. A large hotel chain...
The U.S. Senate Committee on Homeland Security and Governmental Affairs has 15 members. Two members are chosen to serve as the committee chair and the ranking member. Each committee member is equally...
You choose 4 adults at random. What is the probability that none of the four say only a few of their closest family and friends have food allergies or intolerances? Use the pie chart, which shows the...
Three-year-old boys in the United States have a mean height of 38 inches and a standard deviation of 2 inches. How tall is a three-year-old boy with a z-score of -1.0?
Assume a standard Normal distribution. Draw a separate, well-labeled Normal curve for each part. a. Find the z-score that gives a left area of 0.7123. b. Find the z-score that gives a left area of...
Assume the average amount of caffeine consumed daily by adults is normally distributed with a mean of 250 mg and a standard deviation of 48 mg. Determine the percent of adults who consume more than...
Statistics students were conducting a test to see if people could taste the difference between Coke and Pepsi. They fill two cups with Coke and a third with Pepsi. They then asked their subjects...
Express the function in the form f g. u(t) = tan t/1 + tan t
The expected value when you purchase a lottery ticket is -$2.00, and the cost of the ticket is $5.00. Determine the fair price of the lottery ticket.
Nicholas, a mischievous little boy, has removed labels on the eight cans of vegetables in the cabinet. Nicholass father knows that there are three cans of corn, three cans of beans, and two cans of...
Eighty-two percent of people using electronic cigarettes (vapers) are ex-smokers of conventional cigarettes. You randomly select 10 vapers. Find the probability that the first vaper who is an...
What percent of students who took the test have a mathematics score between 550 and 650? Assume that the mathematics scores on a placement test are normally distributed with a mean of 500 and a...
Suppose a poll is done to see if voters agree with a new law passed in Congress. The results are summarized in the 8.1.8 table along with the voters party affiliation. You plan to test to see whether...