Question: The weight of a McDonald’s cheeseburger

> Half of a set of the parts are manufactured by machine A and half by machine B. Four percent of all the parts are defective. Six percent of the parts manufactured on machine A are defective. Find the probability that a part was manufactured on machine A,

> A study showed that 60 percent of The Wall Street Journal subscribers watch CNBC every day. Of these, 70 percent watch it outside the home. Only 20 percent of those who don’t watch CNBC every day watch it outside the home. Let D be the event “watches CNB

> Of grocery shoppers who have a shopping cart, 70 percent pay by credit/debit card (event C1), 20 percent pay cash (event C2), and 10 percent pay by check (event C3). Of shoppers without a grocery cart, 50 percent pay by credit/debit card (event C1), 40 p

> A die is thrown (1, 2, 3, 4, 5, 6) and a coin is tossed (H, T). (a) Enumerate the elementary events in the sample space for the die/coin combination. (b) Are the elementary events equally likely? Explain.

> For a continuous PDF, why can’t we sum the probabilities of all x-values to get the total area under the curve?

> At a Noodles & Company restaurant, the probability that a customer will order a nonalcoholic beverage is .38. Use Excel to find the probability that in a sample of 5 customers (a) none of the 5 will order a nonalcoholic beverage, (b) at least 2 will, (c)

> Based on the previous problem, is major independent of gender? Explain the basis for your conclusion.

> The contingency table below summarizes a survey of 1,000 bottled beverage consumers. Find the following probabilities or percentages: a. Probability that a consumer recycles beverage bottles. b. Probability that a consumer who lives in a state with a de

> Suppose 50 percent of the customers at Pizza Palooza order a square pizza, 80 percent order a soft drink, and 40 percent order both a square pizza and a soft drink. Is ordering a soft drink independent of ordering a square pizza? Explain.

> A hospital’s backup power system has three independent emergency electrical generators, each with uptime averaging 95 percent (some downtime is necessary for maintenance). Any of the generators can handle the hospital’s power needs. Does the overall reli

> A baseball player bats either left-handed (L) or right-handed (R). The player either gets on base (B) or does not get on base (B9). (a) Enumerate the elementary events in the sample space. (b) Would these elementary events be equally likely? Explain.

> The probability that a student has a Visa card (event V) is .73. The probability that a student has a MasterCard (event M) is .18. The probability that a student has both cards is .03. (a) Find the probability that a student has either a Visa card or a M

> Given P(A) = .40, P(B) = .50, and P(A ∩ B) = .05. (a) Find P(A | B). (b) In this problem, are A and B independent?

> Given P(A) = .40, P(B) = .50. If A and B are independent, find P(A ∩ B).

> Given P(J) = .26, P(K) = .48. If A and B are independent, find P(J ∪ K).

> List more than two events (i.e., categorical events) that might describe the outcome of each situation. a. A student applies for admission to Oxnard University. b. A football quarterback throws a pass. c. A bank customer makes an ATM transaction.

> The credit scores of 35-year-olds applying for a mortgage at Ulysses Mortgage Associates are normally distributed with a mean of 600 and a standard deviation of 100. (a) Find the credit score that defines the upper 5 percent. (b) Seventy-five percent of

> A survey asked tax accounting firms their business form (S 5 sole proprietorship, P 5 partnership, C 5 corporation) and type of risk insurance they carry (L 5 liability only, T 5 property loss only, B 5 both liability and property). (a) Enumerate the ele

> List two mutually exclusive events that describe the possible outcomes of each situation. a. A pharmaceutical firm seeks FDA approval for a new drug. b. A baseball batter goes to bat. c. A woman has a mammogram test.

> Suppose the probability of an IRS audit is 1.7 percent for U.S. taxpayers who file form 1040 and who earned $100,000 or more. (a) What are the odds that such a taxpayer will be audited? (b) What are the odds against such a taxpayer being audited?

> Suppose Samsung ships 21.7 percent of the liquid crystal displays (LCDs) in the world. Let S be the event that a randomly selected LCD was made by Samsung. Find (a) P(S), (b) P(S’), (c) the odds in favor of event S, and (d) the odds against event S.

> Given P(A) = .70, P(B) = .30, and P(A ∩ B) = .00, find (a) P(A ∪ B), (b) P(A | B), and (c) P(B | A).

> Given P(A) = .40, P(B) = .50, and P(A ∩ B) = .05, find (a) P(A ∪ B), (b) P(A | B), and (c) P(B | A).

> An entrepreneur who plans to open a Cuban restaurant in Nashville has a 20 percent chance of success.

> Based on the reported experience of climbers from a given year, a climber who attempts Everest has a 31 percent chance of success.

> A credit card customer at Barnes and Noble can use Visa (V), MasterCard (M), or American Express (A). The merchandise may be books (B), electronic media (E), or other (O). (a) Enumerate the elementary events in the sample space describing a customer’s pu

> An exam has a mean of 70 with a standard deviation of 10. Use Chebyshev’s Theorem to find a lower bound for the number of students in a class of 400 who scored between 50 and 90.

> The weights of newborn babies in Foxboro Hospital are normally distributed with a mean of 6.9 pounds and a standard deviation of 1.2 pounds. (a) How unusual is a baby weighing 8.0 pounds or more? (b) What would be the 90th percentile for birth weight? (c

> (a) By Chebyshev’s Theorem, at least how many students in a class of 200 would score within the range μ 6 2σ? (b) By the Empirical Rule, how many students in a class of 200 would score within the range μ 6 2σ? (c) What assumption is required in order to

> Noodles and Company tested consumer reaction to two spaghetti sauces. Each of 70 raters assessed both sauces on a scale of 1 (worst) to 10 (best) using several taste criteria. To correct for possible bias in tasting order, half the raters tasted Sauce A

> Use Excel’s AVEDEV function to find the mean absolute deviation (MAD) of these five numbers: 12, 18, 21, 22, 27.

> Use Excel’s AVEDEV function to find the mean absolute deviation (MAD) of the integers 1 through 10.

> Over the past month, Bob’s bowling score mean was 182 with a standard deviation of 9.1. His bowling partner Cedric’s mean was 152 with a standard deviation of 7.6. Which bowler is more consistent in relative terms?

> (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

> (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

> 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,

> 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.