Last year’s freshman class at Big State University totaled 5,324 students. Of those, 1,254 received a merit scholarship to help offset tuition costs their freshman year (although the amount varied per student). The amount a student received was N($3,456, $478). If the cost of tuition was $4,200 last year, what percentage of students did not receive enough to cover their full tuition?
> (a) Make a scatter plot of the following data on X 5 home size and Y 5 selling price (thousands of dollars) for new homes (n 5 20) in a suburb of an eastern city. (b) Find the sample correlation coefficient. (c) Is there a linear relationship between X a
> In fuel economy tests in city driving conditions, a hybrid vehicle’s mean was 43.2 mpg with a standard deviation of 2.2 mpg. A comparably sized gasoline vehicle’s mean was 27.2 mpg with a standard deviation of 1.9 mpg. Which vehicle’s mpg was more consis
> Your laptop gets warm (even hot) when you place it on your lap because it is dissipating heat from its microprocessor and related components. (a) Use the information in the following table to make a scatter plot. (b) Describe the relationship between Mic
> The number of Internet users in Latin America grew from 78.5 million in 2000 to 156.6 million in 2010. Use the geometric mean to find the annual growth rate.
> An executive’s telephone log showed the lengths of 65 calls initiated during the last week of July. (a) Find the mean, median, mode, midrange, geometric mean, and 10 percent trimmed mean. (b) Are the data symmetric or skewed? If skewed,
> The weight of a small Starbucks coffee is a normally distributed random variable with a mean of 360 grams and a standard deviation of 9 grams. Find the weight that corresponds to each event. Show your work. a. Highest 10 percent b. Middle 50 percent c.
> On Friday night, the owner of Chez Pierre in downtown Chicago noted the amount spent for dinner at 28 four-person tables. (a) Find the mean, midrange, geometric mean, and 10 percent trimmed mean. (b) Do these measures of center agree? Explain. 95 10
> On San Martin Boulevard, embedded sensors kept track of the vehicle traffic count each hour for five weekdays, Monday through Friday between 6 a.m. and 8 p.m. (5 weeks 3 14 hours 5 70 observations). (a) Visually estimate the quartiles Q1, Q2, Q3. (b) Est
> CitiBank recorded the number of customers to use a downtown ATM during the noon hour on 32 consecutive workdays. (a) Find the mean, midrange, geometric mean, and 10 percent trimmed mean. (b) Do these measures of center agree? Explain. 25 37 23 26 30
> Coffee temperatures (degrees Fahrenheit) at a certain restaurant have quartiles Q1 = 160, Q2 = 165, and Q3 = 170. Using the inner fences as a criterion, would a temperature of 149 be considered an outlier?
> Waiting times (minutes) for a table at Joey’s BBQ on Friday at 5:30 p.m. have quartiles Q1 = 21, Q2 = 27 and Q3 = 33. Using the inner fences as a criterion, would a wait time of 45 minutes be considered an outlier?
> In 2007, total compensation (in thousands of dollars) for 40 randomly chosen CEOs ranged from 790 to 192,920, with quartiles Q1 = 3,825, Q2 = 8,890, and Q3 = 17,948. (a) Sketch a simple boxplot (5-number summary without fences) using a nicely scaled X-ax
> Scores on an accounting exam ranged from 42 to 96, with quartiles Q1 = 61, Q2 = 77, and Q3 = 85. (a) Sketch a simple boxplot (5-number summary without fences) using a nicely scaled X-axis. (b) Describe its shape (skewed left, symmetric, skewed right).
> (a) Write the Excel function for the 10 percent trimmed mean of a data set in cells A1:A50. (b) How many observations would be trimmed in each tail? (c) How many would be trimmed overall?
> An executive’s telephone log showed the lengths of 65 calls initiated during the last week of July. (a) Sort the data. (b) Find the mean, median, and mode. (c) Do the measures of center agree? Explain. (d) Are the data symmetric or skew
> (a) Use Excel to make a scatter plot of the data, placing Floor Space on the X-axis and Weekly Sales on the Y-axis. Add titles and modify the default colors, fonts, etc., as you judge appropriate to make the scatter plot effective. (b) Describe the relat
> The weight of a McDonald’s cheeseburger is normally distributed with a mean of 114 ounces and a standard deviation of 7 ounces. Find the weight that corresponds to each event. Show your work. a. Highest 5 percent b. Lowest 50 percent c. Middle 95 perce
> (a) Use Excel to make a scatter plot of the following exam score data, placing Midterm on the X-axis and Final on the Y-axis. Add titles and modify the default colors, fonts, etc., as you judge appropriate to make the scatter plot effective. (b) Describe
> (a) Use Excel to make a scatter plot of these vehicle data, placing Weight on the X-axis and City MPG on the Y-axis. Add titles and modify the default colors, fonts, etc., as you judge appropriate to make the scatter plot effective. (b) Describe the rela
> (a) Use Excel to make a scatter plot of the data for bottled water sales for 10 weeks, placing Price on the X-axis and Units Sold on the Y-axis. Add titles and modify the default colors, fonts, etc., as you judge appropriate to make the scatter plot effe
> (a) Use Excel to prepare a 2-D pie chart for these LCD (liquid crystal display) shipments data. Modify the default colors, fonts, etc., as you judge appropriate to make the display effective. (b) Do you feel that the chart has become too cluttered (i.e.,
> (a) Use Excel to prepare a 2-D pie chart for the following data. Modify the default colors, fonts, etc., as you judge appropriate to make the display effective. (b) Right-click the chart area, select Chart Type, and change to a 3-D pie chart. (c) Right-c
> (a) Use Excel to prepare a Pareto chart of the following data. (b) Which three complaint categories account for approximately 80 percent of all complaints? (c) Which category should the telephone company focus on first? Telephone Company Service Com
> (a) Use Excel to prepare a line chart to display the following gasoline price data. Modify the default colors, fonts, etc., to make the display effective. (b) Change it to a 2-D column chart. Modify the display if necessary to make the display attractive
> (a) Use Excel to prepare a line chart to display the following transplant data. Modify the default colors, fonts, etc., to make the display effective. (b) Describe the pattern, if any. U.S. Organ Transplants, 2000–2010 Year Неart Liver Kidney 13,258
> What problems are evident in the wording of these two questions? What is your race? What is your religious preference? ❏ White ❏ Christian ❏ Black ❏ Jewish
> What would be the difference in student responses to the two questions shown? Version 1: I would prefer that tuition be reduced. Version 2: Cuts in tuition are a good idea even if some classes are canceled.
> The time required to cook a pizza at a neighborhood pizza joint is normally distributed with a mean of 12 minutes and a standard deviation of 2 minutes. Find the time for each event. Show your work. a. Highest 5 percent b. Lowest 50 percent c. Middle 9
> (a) Use Excel to prepare a line chart to display the lightning death data. Modify the default colors, fonts, etc., as you judge appropriate to make the display effective. (b) Describe the pattern, if any. U.S. Deaths by Lightning, 1940–2010 O Lightn
> (a) Use Excel to make a scatter plot of the data, placing Floor Space on the X-axis and Weekly Sales on the Y-axis. Add titles and modify the default colors, fonts, etc., as you judge appropriate to make the scatter plot effective. (b) Describe the relat
> (a) Use Excel to make a scatter plot of the following exam score data, placing Midterm on the X-axis and Final on the Y-axis. Add titles and modify the default colors, fonts, etc., as you judge appropriate to make the scatter plot effective. (b) Describe
> (a) Use Excel to make a scatter plot of these vehicle data, placing Weight on the X-axis and City MPG on the Y-axis. Add titles and modify the default colors, fonts, etc., as you judge appropriate to make the scatter plot effective. (b) Describe the rela
> Suppose you want to study the number of e-mail accounts owned by students in your statistics class. What kind of sample is it if you (a) survey each student who has a student ID number ending in an odd number. (b) survey all the students sitting in the f
> The target population is all students in your university. You wish to estimate the average current Visa balance for each student. How large would the university student population have to be in order to be regarded as effectively infinite in each of the
> The distribution of scores on a statistics exam is T(50, 60, 95). (a) Find the mean. (b) Find the standard deviation. (c) Find the probability that a score will be less than 75. (d) Sketch the distribution and shade the area for the event in part (c).
> The price (dollars per 1,000 board feet) of Douglas fir from western Washington and Oregon varies according to a triangular distribution T(300, 350, 490). (a) Find the mean. (b) Find the standard deviation. (c) What is the probability that the price will
> The distribution of beach condominium prices in Santa Theresa ($ thousands) is T(500, 700, 2,100). (a) Find the mean. (b) Find the standard deviation. (c) Find the probability that a condo price will be greater than $750K. (d) Sketch the distribution and
> In September, demand for industrial furnace boilers at a large plumbing supply warehouse has a mean of 7 boilers with a standard deviation of 2 boilers. The warehouse pays a unit cost of $2,225 per boiler plus a fee of $500 per month to act as dealer for
> The time required to verify and fill a common prescription at a neighborhood pharmacy is normally distributed with a mean of 10 minutes and a standard deviation of 3 minutes. Find the time for each event. Show your work. a. Highest 10 percent b. Middle
> The Rejuvo Corp. manufactures granite countertop cleaner and polish. Quarterly sales Q is a random variable with a mean of 25,000 bottles and a standard deviation of 2,000 bottles. Variable cost is $8 per unit and fixed cost is $150,000. (a) Find the mea
> A manufacturer fills one-gallon cans (3,785 ml) on an assembly line in two independent steps. First, a high-volume spigot injects most of the paint rapidly. Next, a more precise but slower spigot tops off the can. The fill amount in each step is a normal
> The weight of a Los Angeles Lakers basketball player averages 233.1 pounds with a standard deviation of 34.95 pounds. To express these measurements in terms a European would understand, we could convert from pounds to kilograms by multiplying by .4536. (
> Malaprop Ltd. sells two products. Daily sales of product A have a mean of $70 with a standard deviation of $10, while sales of product B have a mean of $200 with a standard deviation of $30. Sales of the products tend to rise and fall at the same time, h
> A certain outpatient medical procedure has five steps that must be performed in sequence. (a) Assuming that the time (in minutes) required for each step is an independent random variable, find the mean and standard deviation for the total time. (b) Why m
> A manufacturing project has five independent phases whose completion must be sequential. The time to complete each phase is a random variable. The mean and standard deviation of the time for each phase are shown below. (a) Find the expected completion ti
> On Professor Hardtack’s last cost accounting exam, the mean score was 71, the median was 77, and the mode was 81. (a) Sketch the distribution, based on these statistics. (b) What factors might cause the distribution to be like this?
> The median life span of a mouse is 118 weeks. (a) Would you expect the mean to be higher or lower than 118? (b) Would you expect the life spans of mice to be normally distributed? Explain.
> At the Eureka library, the mean time a book is checked out is 13 days, the median is 10 days, and the mode is 7 days. (a) Sketch the distribution, based on these statistics. (b) What factors might cause the distribution to be like this?
> At the Midlothian Independent Bank, a study shows that the mean ATM transaction takes 74 seconds, the median 63 seconds, and the mode 51 seconds. (a) Sketch the distribution, based on these statistics. (b) What factors might cause the distribution to be
> A company’s contractual “trigger” point for a union absenteeism penalty is a certain distance above the mean days missed by all workers. Now the company wants to switch the trigger to a certain number of days above the median days missed for all workers.
> A small suburban community agreed to purchase police services from the county sheriff’s department. The newspaper said, “In the past, the charge for police protection from the Sheriff’s Department has been based on the median cost of the salary, fringe b
> The median waiting time for a liver transplant in the United States is 321 days. Would you expect the mean to be higher or lower than 321 days? Explain. (See http://www.livermd.org/.)
> Is this sample of 25 exam scores inconsistent with the hypothesis that the true variance is 64 (i.e., σ = 8)? Use the 5 percent level of significance in a two-tailed test. Show all steps, including the hypotheses and critical values from Appen
> Hammermill Premium Inkjet 24 lb. paper has a specified brightness of 106. (a) At α = .005, does this sample of 24 randomly chosen test sheets from a day’s production run show that the mean brightness exceeds the specificat
> A coin was flipped 60 times and came up heads 38 times. (a) At the .10 level of significance, is the coin biased toward heads? Show your decision rule and calculations. (b) Calculate a p-value and interpret it.
> A U.S. dime weighs 2.268 grams when minted. A random sample of 15 circulated dimes showed a mean weight of 2.256 grams with a standard deviation of .026 gram. (a) Using α = .05, is the mean weight of all circulated dimes lower than the mint weight? State
> Faced with rising fax costs, a firm issued a guideline that transmissions of 10 pages or more should be sent by 2-day mail instead. Exceptions are allowed, but they want the average to be 10 or below. The firm examined 35 randomly chosen fax transmission
> On eight Friday quizzes, Bob received scores of 80, 85, 95, 92, 89, 84, 90, 92. He tells Prof. Hardtack that he is really a 90+ performer, but this sample just happened to fall below his true performance level. (a) State an appropriate pair of hypotheses
> At Ajax Spring Water, a half-liter bottle of soft drink is supposed to contain a mean of 520 ml. The filling process follows a normal distribution with a known process standard deviation of 4 ml. (a) which sampling distribution would you use if random sa
> The cabin of a business jet has a cabin height 5 feet 9 inches high. If a business traveler’s height is N(5’10”, 2.7”), what percentage of the business travelers will have to stoop?
> A can of peeled whole tomatoes is supposed to contain an average of 19 ounces of tomatoes (excluding the juice). The actual weight is a normally distributed random variable whose standard deviation is known to be 0.25 ounce. (a) In quality control, would
> The sodium content of a popular sports drink is listed as 220 mg in a 32-oz bottle. Analysis of 10 bottles indicates a sample mean of 228.2 mg with a sample standard deviation of 18.2 mg. (a) Write the hypotheses for a two-tailed test of the claimed sodi
> Bob said, “Why is a small p-value significant, when a large one isn’t? That seems backwards.” Try to explain it to Bob, giving an example to make your point.
> (a) A statistical study reported that a drug was effective with a p-value of .042. Explain in words what this tells you. (b) How would that compare to a drug that had a p-value of .087?
> A digital camcorder repair service has set a goal not to exceed an average of 5 working days from the time the unit is brought in to the time repairs are completed. A random sample of 12 repair records showed the following repair times (in days): 9, 2, 5
> An auditor reviewed 25 oral surgery insurance claims from a particular surgical office, determining that the mean out-of-pocket patient billing above the reimbursed amount was $275.66 with a standard deviation of $78.11. (a) At the 5 percent level of sig
> In a major football conference, a sample showed that only 267 out of 584 freshmen players graduated within 6 years. (a) At α = .05, does this sample contradict the claim that at least half graduate within 6 years? State your hypotheses and decision rule.
> The EPA is concerned about the quality of drinking water served on airline flights. A sample of 112 flights found unacceptable bacterial contamination on 14 flights. (a) At α = .05, does this sample show that more than 10 percent of all flights have cont
> Ages for the 2009 Boston Red Sox pitchers are shown below. (a) Assuming this is a random sample of major league pitchers, at the 5 percent level of significance does this sample show that the true mean age of all American League pitchers is over 30 years
> A quality control standard requires that no more than 5 percent of bags of Halloween candy be underweight. A random sample of 200 bags showed that 16 were underweight. (a) At α = .025, is the standard being violated? Use a right-tailed test and show your
> Which of the following could not be probability density functions for a continuous random variable? Explain. Hint: Find the area under the function f (x). a. f (x) = .25 for 0 < x < 1 b. f (x) = .25 for 0 < x < 4 c. f (x) = x for 0 < x < 2
> A sample of 100 mortgages approved during the current year showed that 31 were issued to a single-earner family or individual. The historical percentage is 25 percent. (a) At the .05 level of significance in a right-tailed test, has the percentage of sin
> A sample of 100 one-dollar bills from the Subway cash register revealed that 16 had something written on them besides the normal printing (e.g., “Bob Mary”). (a) At α = .05, is this sample evidence consistent with the hypothesis that 10 percent or fewer
> Beer shelf life is a problem for brewers and distributors because when beer is stored at room temperature, its flavor deteriorates. When the average furfuryl ether content reaches 6 μg per liter, a typical consumer begins to taste an unpleasant chemical
> A recent study by the Government Accountability Office found that consumers got correct answers about Medicare only 67 percent of the time when they called 1-800-MEDICARE. (a) At α = .05, would a subsequent audit of 50 randomly chosen calls with 40 corre
> The average service time at a Noodles & Company restaurant was 3.5 minutes in the previous year. Noodles implemented some time-saving measures and would like to know if they have been effective. They sample 20 service times and find the sample average is
> A web-based company has a goal of processing 95 percent of its orders on the same day they are received. If 485 out of the next 500 orders are processed on the same day, would this prove that they are exceeding their goal, using α = .025?
> Malcheon Health Clinic claims that the average waiting time for a patient is 20 minutes or less. A random sample of 15 patients shows a mean wait time of 24.77 minutes with a standard deviation of 7.26 minutes. (a) Write the hypotheses for a right-tailed
> Thetis Mfg. says that its outboard watercraft engine’s noise level at 75 percent throttle averages 100 decibels or less from the operator’s seating position. A random sample of 8 noise level measurements showed a mean of 106 decibels with a standard devi
> Sarpedon Corp. claims that its car batteries average at least 880 CCA (cold-cranking amps). Tests on a sample of 9 batteries yield a mean of 871 CCA with a standard deviation of 15.6 CCA. (a) State the hypotheses to test Sarpedon’s claim against this sam
> Suggest both a Likert scale question and a response scale to measure the following: a. A student’s rating of a particular statistics professor. b. A voter’s satisfaction with the president’s economic policy. c. An HMO patient’s perception of waiting tim
> The weight of a miniature Tootsie Roll is normally distributed with a mean of 3.30 grams and standard deviation of 0.13 gram. (a) Within what weight range will the middle 95 percent of all miniature Tootsie Rolls fall? (b) What is the probability that a
> Historically, 5 percent of a mail-order firm’s repeat charge-account customers have an incorrect current address in the firm’s computer database. (a) What is the probability that none of the next 12 repeat customers who call will have an incorrect addres
> What level of measurement (nominal, ordinal, interval, ratio) is appropriate for the movie rating system that you see in TV Guide (✰, ✰✰, ✰✰✰, ✰✰✰✰)? Explain your reasoning.
> A tabletop survey by a restaurant asked the question shown below. (a) What kind of response scale is this? (b) Suggest an alternative response scale that would be more sensitive to differences in opinion. (c) Suggest possible sources of bias in this type
> Insurance companies are rated by several rating agencies. The Fitch 20-point scale is AAA, AA+, AA, AA-, A+, A, A-, BBB+, BBB, BBB-, BB+, BB, BB-, B+, B, B-, CCC+, CCC, CCC-, DD. (a) What level of measurement does this scale use? (b) To assume that the s
> (a) Use Excel to prepare a Pareto chart of the following data. (b) Which three service providers account for approximately 80 percent of all responses? Cell Phone Service Provider n = 158 O CellPhone Service Provider Percent Cumulative Percent Veriz
> (a) Use Excel to prepare an appropriate type of chart (bar, line, pie, scatter) to display the following data. Modify the default colors, fonts, etc., as you judge appropriate to make the display effective. (b) Would more than one kind of display be acce
> (a) Use Excel to prepare an appropriate type of chart (bar, line, pie, scatter) to display the following data. Modify the default colors, fonts, etc., as you judge appropriate to make the display effective. (b) Would more than one kind of display be acce
> (a) Use Excel to prepare an appropriate type of chart (bar, line, pie, scatter) to display the following data. Modify the default colors, fonts, etc., as you judge appropriate to make the display effective. (b) Would more than one kind of display be acce
> (a) Use Excel to prepare an appropriate type of chart (bar, line, pie, scatter) to display the following data. Modify the default colors, fonts, etc., as you judge appropriate to make the display effective. (b) Would more than one kind of display be acce
> (a) Use Excel to prepare an appropriate type of chart (bar, line, pie, scatter) to display the following data. Modify the default colors, fonts, etc., as you judge appropriate to make the display effective. (b) Would more than one kind of display be acce
> (a) What kind of display is this? (b) Identify its strengths and weaknesses, using the tips and checklists shown in this chapter. (c) Can you suggest any improvements? Would a different type of display be better? Sales of Sony Blu-Ray Disc Players a
> Daily output of Marathon’s Garyville, Lousiana, refinery is normally distributed with a mean of 232,000 barrels of crude oil per day with a standard deviation of 7,000 barrels. (a) What is the probability of producing at least 232,000 barrels? (b) Betwee
> (a) What kind of display is this? (b) Identify its strengths and weaknesses, using the tips and checklists shown in this chapter. (c) Can you suggest any improvements? Would a different type of display be better? U.S. Consumer Bankruptcies 2,500,000
> (a) What kind of display is this? (b) Identify its strengths and weaknesses, using the tips and checklists shown in this chapter. (c) Can you suggest any improvements? Would a different type of display be better? Residential Fire Damage Claims, 2005
> (a) What kind of display is this? (b) Identify its strengths and weaknesses, using the tips and checklists shown in this chapter. (c) Can you suggest any improvements? Would a different type of display be better? Where Do Advertising Dollars Go? Oth
> (a) Use Excel to prepare a Pareto chart of the following data. (b) Which three service providers account for approximately 80 percent of all responses? Cell Phone Service Provider n = 158 O CellPhone Service Provider Percent Cumulative Percent Veriz
> (a) Use Excel to prepare an appropriate type of chart (bar, line, pie, scatter) to display the following data. Modify the default colors, fonts, etc., as you judge appropriate to make the display effective. (b) Would more than one kind of display be acce
> (a) Use Excel to prepare an appropriate type of chart (bar, line, pie, scatter) to display the following data. Modify the default colors, fonts, etc., as you judge appropriate to make the display effective. (b) Would more than one kind of display be acce
