Describe what is meant by an experiment that has a completely randomized design.
> According to the U.S. Census Bureau, in 2009, 10% of adults 25 years and older in the United States had advanced degrees. A researcher with the U.S. Department of Education surveys 500 randomly selected adults 25 years of age or older and finds that 60 o
> Determine the range of the homework data from Problem 1.
> A Gallup survey indicated that 72% of 18- to 29-year-olds, if given a choice, would prefer to start their own business rather than work for someone else. A random sample of 600 18- to 29-year-olds is obtained today. (a) Is the variable start own business
> The Federal Bureau of Investigation classifies various larcenies. The data below represent the type of larcenies based on a random sample of 15 larcenies. What is the mode type of larceny?
> Based on data obtained from AC Nielsen, the mean number of televisions in a household in the United States is 2.24. Assume that the population standard deviation number of television sets in the United States is 1.38. (a) Do you believe the shape of the
> Explain how the standard deviation measures dispersion. In your explanation, include a discussion of deviation about the mean.
> A machine at K&A Tube & Manufacturing Company produces a certain copper tubing component in a refrigeration unit. The tubing components produced by the manufacturer have a mean diameter of 0.75 inch with a standard deviation of 0.004 inch. The quality-co
> The principle of ideomotor action suggests that the act of thinking about a behavior increases the tendency to engage in that behavior. This is sometimes referred to as “priming.” In one such study, 30 male and female undergraduate students were randomly
> Answer the following based on the histograms shown in the next column. (a) Which measure of central tendency would you recommend reporting for the data whose histogram is shown in Figure I? Why? (b) Which one has more dispersion? Explain.
> The total energy need during pregnancy is normally distributed, with mean = 2600 kcal/day and standard deviation= 50 kcal/day. Source: American Dietetic Association. (a) Is total energy need during pregnancy qualitative or quantitative? (b) What is
> The distribution of income tends to be skewed to the right. Suppose you are running for a congressional seat and wish to portray that the average income in your district is low. Which measure of central tendency, the mean or the median, would you report?
> What are the mean and standard deviation of the sampling distribution of /? What are the mean and standard deviation of the sampling distribution of /?
> According to the National Center for Health Statistics, a 10-year-old male whose height is 53.5 inches has a height that is at the 15th percentile. Explain what this means.
> Under what conditions is the sampling distribution of / approximately normal?
> Armando is filling out a college application that requires he supply either his SAT math score or his ACT math score. Armando scored 610 on the SAT math and 27 on the ACT math. Which score should Armando report, given that the mean SAT math score is 515
> Under what conditions is the sampling distribution of / normal?
> The following data represent the amount of time (in minutes) a random sample of eight students enrolled in Sullivan’s Intermediate Algebra course spent on the homework from Section 4.5, Factoring Polynomials. (a) Determine the mean amount of time spent d
> Suppose, during the course of a typical season, a batter has 500 at-bats. This means the player has the opportunity to get a hit 500 times during the course of a season. Further, suppose a batter is a career 0.280 hitter (he averages 280 hits every 1000
> To help assess student learning in her developmental math courses, a mathematics professor at a community college implemented pre- and posttests for her students. A knowledge-gained score was obtained by taking the difference of the two test scores. (a)
> The following is a USA Today-type graph. Do you think the graph is misleading? Why? If you think it is misleading, improve the graph?
> In your own words, explain what a sampling distribution is.
> The data in the next column shows birth rate and per capita income (in thousands of 2012 dollars) from 2005 through 2017. Draw a time-series plot for both birth rate and per capita income. Comment on any trends.
> = 70, = 10, P(65 < X < 85)
> = 30, = 5, P(X ≤ 23)
> The following data represent the time (in minutes) students spent working their Section 1.1 homework from Sullivan’s College Algebra course (based on time logged into MyLabMath). Draw a stem-and-leaf diagram of the data and comment on the shape of the di
> = 50, = 6, PX 55
> Dr. Paul Oswiecmiski randomly selects 40 of his 20- to 29-year-old patients and obtains the following data regarding their serum HDL cholesterol: (a) Construct a frequency distribution. (b) Construct a relative frequency distribution. (c) Construct a fre
> Find the value of z0.20.
> The following data represent the number of cars that arrived at a McDonald’s drive-through between 11:50 A.M. and 12:00 noon each Wednesday for the past 50 weeks: (a) Construct a frequency distribution of the data. (b) Construct a relative frequency dist
> An ad for Crest Whitestrips Premium claims that the strips will whiten teeth in 7 days and the results will last for 12 months. A researcher who wishes to test this claim studies 20 sets of identical twins. Within each set of twins, one is randomly selec
> Length (in minutes) of a country song
> Find the z-scores that separate the middle 92% of the data from the area in the tails of the standard normal distribution.
> Interested in knowing the educational background of its customers the Metra Train Company contracted a marketing firm to conduct a survey asking 50 randomly selected commuters at the train station to disclose their educational attainment. The results sho
> Find the z-score such that the area to the right of the z-score is 0.483.
> A random sample of 1005 adult Americans was asked, “How would you prefer to pay for new road construction?” Results of the survey are below. (a) Construct a relative frequency distribution. (b) What percent of the respondents indicated they would like to
> The area between z = -0.34 and z = 1.03.
> The graph shows the ratings on Yelp for Hot Doug’s Restaurant. (a) Which was the most popular rating for Hot Doug’s? (b) How many ratings were posted on Hot Doug’s? (c) How many more 5 Star ratings are there than 4 Star ratings? (d) What percentage of ra
> Explain how to use a normal probability plot to assess normality.
> Explain the difference between a lurking variable and a confounding variable.
> The area to the left of z = -1.04.
> Researchers Katherine Tucker and associates wanted to determine whether consumption of cola is associated with lower bone mineral density. They looked at 1125 men and 1413 women in the Framingham Osteoporosis Study, which is a cohort that began in 1971.
> A pharmaceutical company has developed an experimental drug meant to relieve symptoms associated with the common cold. The company identifies 300 adult males 25 to 29 years old who have a common cold and randomly divides them into two groups. Group 1 is
> List the properties of the normal density curve.
> Nucryst Pharmaceuticals, Inc., announced the results of its first human trial of NPI 32101, a topical form of its skin ointment. A total of 225 patients diagnosed with skin irritations were randomly divided into three groups as part of a double-blind, pl
> A continuous random variable X is uniformly distributed with / (a) Draw a graph of the uniform density function. (b) What is / (c) What is /
> Does the shape of a glass play a role in determining the amount of time it takes to finish the drink? Researchers identified 159 male and female self- professed social drinkers. One week the subjects were given a 12 ounce beer with either a straight g
> According to a USA Today “Snapshot,” 20% of adults surveyed do their most creative thinking while driving. You conduct a survey of 250 adults and find that 30 do their most creative thinking while driving. (a) Compute the probability that, in a random sa
> Each of the following surveys has bias. Identify the type of bias. (a) A television survey that gives 900 phone numbers for viewers to call with their vote. Each call costs $2.00. (b) An employer distributes a survey to her 450 employees asking them how
> In 1798, Henry Cavendish obtained 27 measurements of the density of Earth, using a torsion balance. The following data represent his estimates, given as a multiple of the density of water. Is it reasonable to conclude that the sample data come from a pop
> Hector obtained a random sample of twenty recent college graduates who own cars and asked each to disclose the age of their car (in months). Is it reasonable to conclude that age of car is normally distributed? The normal probability plot is shown below
> Use the results in the table to (a) draw a normal plot, (b) determine the linear correlation between the observed values and expected z-scores, (c) determine the critical value in Table VI to assess the normality of the data.
> A school psychologist wants to test the effectiveness of a new method for teaching reading. She recruits 500 first-grade students in District 203 and randomly divides them into two groups. Group 1 is taught by means of the new method, while group 2 is ta
> A casino manager wants to inspect a sample of 14 slot machines in his casino for quality-control purposes. There are 600 sequentially numbered slot machines operating in the casino. Obtain a systematic sample of 14 slot machines. Be sure to discuss how y
> According to a Gallup poll, 46% of Americans 18 years old or older stated that they had read at least six books (fiction and nonfiction) within the past year. You conduct a random sample of 250 Americans 18 years old or older and ask the individuals to d
> A farmer has a 500-acre orchard in Florida. Each acre is subdivided into blocks of 5. Altogether, there are 2500 blocks of trees on the farm. After a frost, he wants to get an idea of the extent of the damage. Obtain a sample of 10 blocks of trees using
> According to Major League Baseball rules, the ball must weigh between 5 and 5.25 ounces. A factory produces baseballs whose weights are approximately normally distributed, with mean 5.11 ounces and standard deviation 0.062 ounce. Source: www.baseball-alm
> A congresswoman wants to survey her constituency regarding public policy. She asks one of her staff members to obtain a sample of residents of the district. The frame she has available lists 9012 Democrats, 8302 Republicans, and 3012 Independents. Obtain
> The Wechsler Intelligence Scale for Children is approximately normally distributed, with mean 100 and standard deviation 15. (a) What is the probability that a randomly selected test taker will score above 125? (b) What is the probability that a randomly
> A cellular phone company is looking for ways to improve customer satisfaction. They want to select a simple random sample of four stores from their 15 franchises in which to conduct customer satisfaction surveys. Discuss the procedure you would use, and
> Suppose that Dunlop Tire manufactures a tire with a lifetime that approximately follows a normal distribution with mean 70,000 miles and standard deviation 4400 miles. (a) What proportion of the tires will last at least 75,000 miles? (b) Suppose that Dun
> List the steps required to conduct an experiment.
> Use the figure to answer the questions that follow. (a) What is ? (b) What is ? (c) Suppose that the area under the normal curve to the right of x = 75 is 0.0668. Provide two interpretations for this area. (d) Suppose that the area under the normal cur
> To determine if topiramate is a safe and effective treatment for alcohol dependence, researchers conducted a 14-week trial of 371 men and women aged 18 to 65 years diagnosed with alcohol dependence. In this double-blind, randomized, placebo-controlled ex
> Explain why it is important to use a control group and blinding in an experiment.
> State the condition required to use the Empirical Rule to check for unusual observations in a binomial experiment.
> Compare and contrast observational studies and designed experiments. Which study allows a researcher to claim causality?
> Consider a binomial probability distribution with parameters n = 8 and p = 0.75. (a) Construct a binomial probability distribution with these parameters. (b) Compute the mean and standard deviation of the distribution. (c) Graph the discrete probability
> Contrast the three major types of observational studies in terms of the time frame when the data are collected.
> According to a Gallup poll, 60% of U.S. women 18 years old or older stated that the minimum driving age should be 18. In a random sample of 15 U.S. women 18 years old or older, find the probability that: (a) Exactly 10 believe that the minimum driving ag
> A pollster asks 800 adult Americans whether the gap between the rich and poor will grow or shrink over the next 30 years.
> The probability that a randomly selected patient who visits the emergency room (ER) will die within 1 year of the visit is 0.05. Source: SuperFreakonomics. (a) What is the probability that exactly 1 of 10 randomly selected visitors to the ER will die wit
> A random sample of 30 digital cameras is selected and divided into two groups. One group uses a brand-name battery, while the other uses a generic plain-label battery. All variables besides battery type are controlled. Pictures are taken under identical
> Determine whether the probability experiment represents a binomial experiment. If not, explain why. (a) According to the Chronicle of Higher Education, the probability that a randomly selected incoming freshman will graduate from college within 6 years i
> Researchers wanted to determine the association between number of times one chews food and food consumption. They identified 45 individuals who were 18 to 45 years of age. First, the researchers determined a baseline for number of chews before swallowing
> The number of surface imperfections on a camera lens.
> A popular casino table game is three-card poker. One aspect of the game is the “pair plus” bet in which a player is paid a dollar amount for any hand of a pair or better, regardless of the hand the dealer has. The table shows the profit and probability o
> Video game rating system by the Entertainment Software Rating Board (EC, E, E10 +, T, M, AO, RP)
> The Stanley Cup is a best-of-seven series to determine the champion of the National Hockey League. The following data represent the number of games played, X, in the Stanley Cup before a champion was determined from 1939 to 2019. Note: There was no champ
> Determine whether the distribution is a discrete probability distribution. If not, state why.
> According to the article “Self-injurious Behaviors in a College Population,” 17% of undergraduate or graduate students have had at least one incidence of self- injurious behavior. The researchers conducted a survey of 40 college students who reported a h
> In sampling from finite populations without replacement, the assumption of independence required for a binomial experiment is violated. Under what circumstances can we sample without replacement and still use the binomial probability formula to approxima
> Determine whether the random variable is discrete or continuous. In each case, state the possible values of the random variable. (a) The number of students in a randomly selected elementary school classroom (b) The amount of snow that falls in Minneapoli
> Suppose that P(E) = 0.8, P(F) = 0.5, and P(E and F) = 0.24. Are events E and F independent? Why?
> Suppose that events E and F are independent. In addition, P(E) = 0.45 and P(F) = 0.2. What is P(E and F)?
> Generally, the goal of an experiment is to determine the effect that treatments will have on the response variable.
> Suppose that P(E) = 0.36, P(F) = 0.12, and E and F are mutually exclusive. What is P(E or F)?
> Suppose that P(E) = 0.76, P(F) = 0.45, and P(E and F) = 0.32. What is P(E or F)?
> Suppose that E = {yellow}. Compute the probability of Ec.
> E = {red or blue or yellow}
> (a) Patti and John each played 100 games of Solitaire on their smart phone. Patti won 7 of her games and estimated the probability of winning Solitaire as 0.07. John won 6 of his games and estimated the probability of winning Solitaire as 0.06. Why are t
> The following data represent the number of cases of coffee or filters sold by four sales reps in a recent sales competition. (a) What is the probability that a randomly selected case was sold by Bryce? Is this unusual? (b) What is the probability that a
> In 1996, a New York couple won $2.5 million in the state lottery. Eleven years later, the couple won $5 million in the state lottery using the same set of numbers. The odds of winning the New York lottery twice are roughly 1 in 16 trillion, described by
> During the 1998 Major League Baseball season, Mark McGwire of the St. Louis Cardinals hit 70 home runs. Of the 70 home runs, 34 went to left field, 20 went to left center field, 13 went to center field, 3 went to right center field, and 0 went to right f
> F = {green or orange}
> In the game of five-card stud, one card is dealt face down to each player and the remaining four cards are dealt face up. After two cards are dealt (one down and one up), the players bet. Players continue to bet after each additional card is dealt. Suppo
> Distinguish between nonsampling error and sampling error.
> Explain what is meant by a subjective probability. List some examples of subjective probabilities.
> Use a graphing calculator or statistical software to simulate the playing of the game of roulette, using an integer distribution with numbers 1 through 38. Repeat the simulation 100 times. Let the number 37 represent 0 and the number 38 represent 00. Use
> Because of a mistake in packaging, a case of 12 bottles of red wine contained five Merlot and seven Cabernet, each without labels. All the bottles look alike and have an equal probability of being chosen. Three bottles are randomly selected. (a) What is
> In one of Arizona’s lotteries, balls are numbered 1–35. Five balls are selected randomly, without replacement. The order in which the balls are selected does not matter. To win, your numbers must match the five selected. Determine your probability of win
