Question: The data set “Tornadoes_2017” located at www.

> Violent crimes include rape, robbery, assault, and homicide. The following is a summary of the violent-crime rate (violent crimes per 100,000 population) for all 50 states in the United States plus Washington, D.C., in 2017. Q1 = 244.8 Q2 = 357.6 Q3 =

> Explain the meaning of the following percentiles. Source: National Center for Health Statistics. (a) The 5th percentile of the weight of males 36 months of age is 12.0 kg. (b) The 95th percentile of the length of newborn females is 53.8 cm.

> The data set “Tornadoes_2017” located at www.pearsonhighered.com/ sullivanstats contains a variety of variables that were measured for all tornadoes in the United States in 2017. For each of the following variables in the data set, indicate the level of

> Explain the meaning of the following percentiles. Source: Advance Data from Vital and Health Statistics. (a) The 15th percentile of the head circumference of males 3 to 5 months of age is 41.0 cm. (b) The 90th percentile of the waist circumference of fem

> A manufacturer of bolts has a quality- control policy that requires it to destroy any bolts that are more than 2 standard deviations from the mean. The quality-control engineer knows that the bolts coming off the assembly line have a mean length of 8 cm

> A highly selective boarding school will only admit students who place at least 1.5 standard deviations above the mean on a standardized test that has a mean of 200 and a standard deviation of 26. What is the minimum score that an applicant must make on t

> Roberto finishes a triathlon (750-meter swim, 5-kilometer run, and 20-kilometer bicycle) in 63.2 minutes. Among all men in the race, the mean finishing time was 69.4 minutes with a standard deviation of 8.9 minutes. Zandra finishes the same triathlon in

> Ryan Murphy, nephew of the author, swims for U.S.A. Swimming. While he was in college at the University of California at Berkeley, Ryan’s best time in the 100-meter backstroke was 45.3 seconds. The mean of all NCAA swimmers in this event is 48.62 seconds

> The highest batting average ever recorded in Major League Baseball was by Ted Williams in 1941 when he hit 0.406. That year, the mean and standard deviation for batting average were 0.2806 and 0.0328. In 2018, Mookie Betts was the American League batting

> In 2018, Jacob deGrom of the New York Mets had the lowest earned-run average (ERA is the mean number of runs yielded per nine innings pitched) of any starting pitcher in the National League, with an ERA of 1.70. Also in 2018, Blake Snell of the Tampa Bay

> The average 20- to 29-year-old man is 69.6 inches tall, with a standard deviation of 3.0 inches, while the average 20- to 29-year-old woman is 64.1 inches tall, with a standard deviation of 3.8 inches. Who is relatively taller, a 67-inch man or a 62-inch

> The average 20- to 29-year-old man is 69.6 inches tall, with a standard deviation of 3.0 inches, while the average 20- to 29-year-old woman is 64.1 inches tall, with a standard deviation of 3.8 inches. Who is relatively taller, a 75-inch man or a 70-inch

> Babies born after a gestation period of 32–35 weeks have a mean weight of 2600 grams and a standard deviation of 660 grams. Babies born after a gestation period of 40 weeks have a mean weight of 3500 grams and a standard deviation of 470 grams. Suppose a

> The data set “Tornadoes_2017” located at www.pearsonhighered.com/ sullivanstats contains a variety of variables that were measured for all tornadoes in the United States in 2017. For each of the following variables in the data set, indicate whether the v

> Babies born after a gestation period of 32–35 weeks have a mean weight of 2600 grams and a standard deviation of 660 grams. Babies born after a gestation period of 40 weeks have a mean weight of 3500 grams and a standard deviation of 470 grams. Suppose a

> The_______ is the range of the middle 50% of the observations in a data set.

> Often, frequency distributions are reported using unequal class widths because the frequencies of some groups would otherwise be small or very large. Consider the following data, which represent the daytime household temperature the thermostat is set to

> The frequency distribution below represents the square footage of a random sample of 500 houses that are owner occupied year round. Approximate the mean and standard deviation square footage.

> Recently, a random sample of 25–34 year olds was asked, “How much do you currently have in savings, not including retirement savings?” The following data represent the responses to the survey. Approximate the mean and standard deviation amount of savings

> Determine the modal class of the frequency distribution in Problem 2.

> Determine the modal class of the frequency distribution in Problem 1.

> Approximate the median of the frequency distribution in Problem 4.

> Approximate the median of the frequency distribution in Problem 2.

> The following data represent the age of the mother at childbirth for 1980 and 2017. (a) Approximate the population mean and standard deviation of age for mothers in 1980. (b) Approximate the population mean and standard deviation of age for mothers in 20

> The Gallup Organization conducted a survey of 1018 adults, aged 18 and older, living in the United States and asked, “If you had a thousand dollars to spend, do you think investing it in the stock market would be a good or bad idea?” Of the 1018 adults,

> The data represent the male and female population, by age, of the United States in 2017. Note: Use 85 for the class midpoint of Ú 80. (a) Approximate the population mean and standard deviation of age for males. (b) Approximate the population mean and sta

> Michael and Kevin return to the candy store, but this time they want to purchase nuts. They can’t decide among peanuts, cashews, or almonds. They again agree to create a mix. They bought 2.5 pounds of peanuts for $1.30 per pound, 4 pounds of cashews for

> Michael and Kevin want to buy chocolates. They can’t agree on whether they want chocolate- covered almonds, chocolate-covered peanuts, or chocolate- covered raisins. They agree to create a mix. They bought 4 pounds of chocolate-covered almonds at $3.50 p

> In Marissa’s calculus course, attendance counts for 5% of the grade, quizzes count for 10% of the grade, exams count for 60% of the grade, and the final exam counts for 25% of the grade. Marissa had a 100% average for attendance, 93% for quizzes, 86% for

> Marissa has just completed her second semester in college. She earned a B in her five-hour calculus course, an A in her three-hour social work course, an A in her four-hour biology course, and a C in her three-hour American literature course. Assuming th

> Use the frequency distribution whose class width is 0.5 obtained in Problem 30 in Section 2.2 to approximate the mean and standard deviation for cigarette tax rates. Compare these results to the actual mean and standard deviation.

> Use the frequency distribution whose class width is 4 obtained in Problem 29 in Section 2.2 to approximate the mean and standard deviation exit velocity. Compare these results to the actual mean and standard deviation exit velocity.

> The following frequency distribution represents the birth weight of all babies born in the United States in 2017. (a) Approximate the mean and standard deviation birth weight. (b) Draw a frequency histogram of the data to verify that the distribution is

> The following data represent the number of live multiple-delivery births (three or more babies) in 2017 for women 15 to 54 years old. (a) Approximate the mean and standard deviation for age. (b) Draw a frequency histogram of the data to verify that the d

> The following frequency distribution represents the age of people living in poverty in 2018 based on a random sample of residents of the United States. In this frequency distribution, the class widths are not the same for each class. Approximate the mean

> Gallup News Service conducted a survey of 1017 American adults aged 18 years or older. The respondents were asked, “Of every tax dollar that goes to the federal government in Washington, D.C., do you believe 51 cents or more are wasted?” Of the 1017 indi

> The sum of the deviations about the mean always equals_____ .

> In 2000, the Walt Disney Company created the “fast pass” —a ticket issued to a rider for a popular ride and the rider is told to return at a specific time during the day. At that time, the rider is allowed to bypass the regular line, thereby reducing the

> Draw two histograms with different standard deviations and label them I and II. Which histogram has the larger standard deviation?

> Develop a sample of size n = 8 such that /and s = 0.

> Which of the following would have a higher standard deviation? (a) IQ of students on your campus or (b) IQ of residents in your home town? Why?

> Explain how standard deviation measures spread. In your explanation include the computation of the same standard deviation for two data sets: Data set I: 3, 4, 5; Data set II: 0, 4, 8.

> In one of Sullivan’s statistics sections, the standard deviation of the heights of all students was 3.9 inches. The standard deviation of the heights of males was 3.4 inches and the standard deviation of females was 3.3 inches. Why is the standard deviat

> What makes the range less desirable than the standard deviation as a measure of dispersion?

> What does it mean when a statistic is biased?

> Are any of the measures of dispersion mentioned in this section resistant? Explain.

> A study was designed “to determine if application of duct tape is as effective as cryotherapy (liquid nitrogen applied to the wart for 10 seconds every 2 to 3 weeks) in the treatment of common warts.” The researchers randomly divided 51 patients into two

> What is meant by the phrase degrees of freedom as it pertains to the computation of the sample standard deviation?

> Would it be appropriate to say that a distribution with a standard deviation of 10 centimeters is more dispersed than a distribution with a standard deviation of 5 inches? Support your position.

> Survey Choose any quantitative variable from the SullivanStatsSurveyI at www.pearsonhighered.com/sullivanstats. Now choose a qualitative variable, such as gender or political philosophy. Determine the range and standard deviation by the qualitative varia

> Choose two quantitative variables from the SullivanStatsSurveyI at www.pearsonhighered.com/sullivanstats for which a comparison is reasonable, such as number of hours of television versus number of hours of Internet. Draw a histogram for each variable. W

> The data set on the left represents the annual rate of return (in percent) of eight randomly sampled bond mutual funds, and the data set on the right represents the annual rate of return (in percent) of eight randomly sampled stock mutual funds. (a) Dete

> A popular theory in investment states that you should invest a certain amount of money in foreign investments to reduce your risk. The risk of a portfolio is defined as the standard deviation of the rate of return. Refer to the graph, which depicts the r

> Karl Pearson developed a measure that describes the skewness of a distribution, called the coefficient of skewness. The formula is The value of this measure generally lies between -3 and +3. The closer the value lies to -3, the more the distribution is s

> Another measure of variation is the mean absolute deviation. It is computed using the formula Compute the mean absolute deviation of the data in Problem 11 and compare the results with the sample standard deviation.

> Blocking refers to the idea that we can reduce the variability in a variable by segmenting the data by some other variable. The given data represent the recumbent length (in centimeters) of a sample of 10 males and 10 females who are 40 months of age. (a

> A study was conducted in which 20,211 18-year- old Israeli male military recruits were given an exam to measure IQ. In addition, the recruits were asked to disclose their smoking status. An individual was considered a smoker if he smoked at least one cig

> The following data represent the asking price, in dollars, for a random sample of 2014 coupes (a two-door car) and a random sample of 2014 Chevy Camaros. (a) Find the mean and standard deviation price for each sample. (b) Explain why the mean is higher f

> Compute the sample standard deviation of the following test scores: 78, 78, 78, 78. What can be said about a data set in which all the values are identical?

> Each of the following three data sets represents the IQ scores of a random sample of adults. IQ scores are known to have a mean and median of 100. For each data set, determine the sample standard deviation. Then recompute the sample standard deviation as

> Benjamin owns a small Internet business. Besides himself, he employs nine other people. The salaries earned by the employees are given next in thousands of dollars (Benjamin’s salary is the largest, of course): 30, 30, 45, 50, 50, 50, 55, 55, 60, 75 (a)

> The standard deviation of batting averages of all teams in the American League is 0.008. The standard deviation of all players in the American League is 0.02154. Why is there less variability in team batting averages?

> According to the U.S. Census Bureau, the mean of the commute time to work for a resident of Boston, Massachusetts, is 27.3 minutes. Assume that the standard deviation of the commute time is 8.1 minutes to answer the following: (a) What minimum percentage

> In December 2018, the average price of regular unleaded gasoline excluding taxes in the United States was $3.06 per gallon, according to the Energy Information Administration. Assume that the standard deviation price per gallon is $0.06 per gallon to ans

> Lawrence Summers (former Secretary of the Treasury and former president of Harvard) infamously claimed that women have a lower standard deviation IQ than men. He went on to suggest that this was a potential explanation as to why there are fewer women in

> Suppose Professor Alpha and Professor Omega each teach Introductory Biology. You need to decide which professor to take the class from and have just completed your Introductory Statistics course. Records obtained from past students indicate that students

> The distribution of the length of bolts has a bell shape with a mean of 4 inches and a standard deviation of 0.007 inch. (a) About 68% of bolts manufactured will be between what lengths? (b) What percentage of bolts will be between 3.986 inches and 4.014

> The following information relates to the 2019 model year product line of BMW automobiles.

> In a national survey on substance abuse, 13.3% of 12th graders reported using illicit drugs within the past month. Source: National Institute on Drug Abuse

> The weight, in grams, of the pair of kidneys in adult males between the ages of 40 and 49 has a bell- shaped distribution with a mean of 325 grams and a standard deviation of 30 grams. (a) About 95% of kidney pairs will be between what weights? (b) What

> SAT Math scores have a bell-shaped distribution with a mean of 515 and a standard deviation of 114. Source: College Board. (a) What percentage of SAT scores is between 401 and 629? (b) What percentage of SAT scores is less than 401 or greater than 629? (

> The Stanford—Binet Intelligence Quotient (IQ) measures intelligence. IQ scores have a bell-shaped distribution with a mean of 100 and a standard deviation of 15. (a) What percentage of people has an IQ score between 70 and 130? (b) What percentage of peo

> It is well known that San Diego has milder weather than Chicago, but which city has more deviation from normal temperatures? Use the following data, which represent the deviation from normal high temperatures for a random sample of days. In which city wo

> Stocks may be categorized by sectors. Go to www.pearsonhighered.com/sullivanstats and download 3_2_29 using the file format of your choice. The data represent the one-year rate of return (in percent) for a sample of consumer cyclical stocks and industria

> You have received a year-end bonus of $5000. You decide to invest the money in the stock market and have narrowed your investment options down to two mutual funds. The following data represent the historical quarterly rates of return of each mutual fund

> Suppose that you are in the market to purchase a car. You have narrowed it down to two choices and will let gas mileage be the deciding factor. You decide to conduct a little experiment in which you put 10 gallons of gas in the car and drive it on a clos

> The following data represent the length of eruption for a random sample of eruptions at the Old Faithful geyser in Calistoga, California. (a) Determine the sample standard deviation length of eruption. Express your answer rounded to the nearest whole num

> The following data represent the weights (in grams) of a random sample of 50 M&M plain candies. (a) Determine the sample standard deviation weight. Express your answer rounded to three decimal places. (b) On the basis of the histogram drawn in Section 3.

> The data below represent the number of pods on a sample of soybean plants for two different plot types. Which plot type do you think is superior? Why?

> The following data represent driver’s license laws for various states.

> Ethan and Drew went on a 10-day fishing trip. The number of smallmouth bass caught and released by the two boys each day was as follows: (a) Find the population mean and the range for the number of smallmouth bass caught per day by each fisherman. Do the

> The following data represent the travel time (in minutes) to school for nine students enrolled in Sullivan’s College Algebra course. Treat the nine students as a population. (a) Determine the population standard deviation. (b) Find three simple random sa

> The data represent the pulse rates (beats per minute) of nine students enrolled in a section of Sullivan’s course in Introductory Statistics. Treat the nine students as a population. (a) Determine the population standard deviation. (b) Find three simple

> The acidity or alkalinity of a solution is measured using pH. A pH less than 7 is acidic, while a pH greater than 7 is alkaline. The following data represent the pH in samples of bottled water and tap water. (a) Which type of water has more dispersion in

> The following data represent exam scores in a statistics class taught using traditional lecture and a class taught using a “flipped” classroom. The “flipped” classroom is one where the content is delivered via video and watched at home, while class time

> (a) Suppose in a certain set of data, there are two observations of 90 and 100. Is 90 far away from 100 if the standard deviation of the data is 10? (b) Suppose in a certain set of data, there are two observations of 90 and 100. Is 90 far away from 100 i

> For each of the following data sets, decide which has the higher standard deviation (set 1 or set 2), if any, without doing any computation. Explain the rationale behind your choice. Then, verify your choice by computing the standard deviation by hand.

> Match the histograms in the next column to the summary statistics given.

> Which histogram depicts a higher standard deviation? Justify your answer.

> The following data represent the flight time (in minutes) of a random sample of seven flights from Las Vegas, Nevada, to Newark, New Jersey, on United Airlines. Compute the range and sample standard deviation of flight time. 282, 270, 260, 266, 257, 260,

> A community college notices that an increasing number of full-time students are working while attending the school. The administration randomly selects 128 students and asks how many hours per week each works.

> A certain type of concrete mix is designed to withstand 3000 pounds per square inch (psi) of pressure. The strength of concrete is measured by pouring the mix into casting cylinders after it is allowed to set up for 28 days. The following data represent

> The following data represent the amount of time (in minutes) a random sample of eight students took to complete the online portion of an exam in Sullivan’s Statistics course. Compute the range, sample variance, and sample standard deviation time. 60.5, 1

> The following data represent the miles per gallon for a 2013 Ford Fusion for six randomly selected vehicles. Compute the range, sample variance, and sample standard deviation miles per gallon. Source: www.fueleconomy.gov 34.0, 33.2, 37.0, 29.4, 23.6, 25.

> Population: 4, 10, 12, 12, 13, 21

> Sample: 6, 52, 13, 49, 35, 25, 31, 29, 31, 29

> Population: 1, 19, 25, 15, 12, 16, 28, 13, 6

> Population: 3, 6, 10, 12, 14

> Sample: 83, 65, 91, 87, 84

> Sample: 20, 13, 4, 8, 10