Questions and Answers of Introductory Statistics Exploring The World Through Data

In a 2017 Harris poll conducted for Uber Eats, 438 of 1019 U.S. adults polled said they were “picky eaters.”a. What proportion of the respondents said they were picky eaters?b. Find a 95%
The website www.mlb.com compiles statistics on all professional baseball players. For the 2017 season, statistics were recorded for all 663 players. Of this population, the mean batting average was
The Gallup poll reported that 45% of Americans have tried marijuana. This was based on a survey of 1021 Americans and had a margin of error of plus or minus 5 percentage points with a 95% level of
According to a 2018 Rasmussen Poll, 40% of American adults were very likely to watch some of the Winter Olympic coverage on television. The survey polled 1000 American adults and had a margin of
A 2017 survey of U.S. adults found the 64% believed that freedom of news organization to criticize political leaders is essential to maintaining a strong democracy. Assume the sample size was 500.a.
A 2017 survey of U.S. adults found that 74% believed that protecting the rights of those with unpopular views is a very important component of a strong democracy. Assume the sample size was 1000.a.
A 2016 Pew Research poll found that 61% of U.S. adults believe that organic produce is better for health than conventionally grown varieties. Assume the sample size was 1000 and that the conditions
A 2017 Gallup poll reported that 658 out of 1028 U.S. adults believe that marijuana should be legalized. When Gallup first polled U.S. adults about this subject in 1969, only 12% supported
The 2017 Chapman University Survey of American Fears asked a random sample of 1207 adults Americans if they believed that aliens had come to Earth in modern times, and 26% responded yes.a. What is
According to a 2017 Gallup poll, 572 out of 1021 randomly selected smokers polled believed they are discriminated against in public life or in employment because of their smoking.a. What percentage
According to a 2017 Gallup Poll, 617 out of 1028 randomly selected adults living in the United States felt the laws covering the sale of firearms should be more strict.a. What is the value of pn, the
A 2017 Gallup poll found that 601 out of 1018 randomly selected adults in the United States said protection of the environment should be given priority over development of U.S. energy supplies such
A recent Monmouth University poll found that 675 out of 1008 randomly selected people in the United States felt that college and universities with big sports programs placed too much emphasis on
Human blood is divided into 8 possible blood types. The rarest blood type is AB negative. Only 1% of the population has this blood type. Suppose a random sample of 50 people is selected. Can we find
While the majority of people who are color blind are male, the National Eye Institute reports that 0.5% of women of with Northern European ancestry have the common form of red-green color blindness.
According to data released in 2016, 69% of students in the United States enroll in college directly after high school graduation. Suppose a sample of 200 recent high school graduates is randomly
According to a 2017 Gallup poll, 80% of Americans report being afflicted by stress. Suppose a random sample of 1000 Americans is selected.a. What percentage of the sample would we expect to report
In 2018 it was estimated that approximately 45% of the American population watches the Super Bowl yearly. Suppose a sample of 120 Americans is randomly selected. After verifying the conditions for
According to a 2018 Pew Research Center report on social media use, 28% of American adults use Instagram. Suppose a sample of 150 American adults is randomly selected. We are interested in finding
According to a 2017 Pew Research Center report on voting issues, 59% of Americans feel that the everything should be done to make it easy for every citizen to vote. Suppose a random sample of 200
According to a 2017 survey conducted by Netflix, 46% of couples have admitted to “cheating” on their significant other by streaming a TV show ahead of their partner. Suppose a random sample of 80
According to a 2017 Pew Research survey, 60% of young Americans aged 18 to 29 say the primary way they watch television is through streaming services on the Internet. Suppose a random sample of 200
According to a 2018 Pew Research report, 40% of Americans read print books exclusively (rather than reading some digital books). Suppose a random sample of 500 Americans is selected.a. What
According to a 2017 Pew Research report, 40% of millennials have a BA degree. Suppose we take a random sample of 500 millennials and find the proportion who have a driver’s license. Find the
According to a 2017 article in The Washington Post, 72% of high school seniors have a driver’s license. Suppose we take a random sample of 100 high school seniors and find the proportion who have a
Suppose it is known that 60% of employees at a company use a Flexible Spending Account (FSA) benefit.a. If a random sample of 200 employees is selected, do we expect that exactly 60% of the sample
Suppose it is known that 20% of students at a certain college participate in a textbook recycling program each semester.a. If a random sample of 50 students is selected, do we expect that exactly 20%
Assuming that the true proportion of success for the trials shown in the graph for Exercise 7.33 is 0.2, explain whether any of the graphs shows bias.Data From Exercise 7.33: A B 0.0 0.1 0.2 0.3 0.4
Which of the dotplots given in Exercise 7.33 has the largest standard error, and which has the smallest standard error?Data From Exercise 7.33: A B 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Sample
In the graphs for Exercise 7.33, explain how you can tell from the shape of the graph which has the largest sample size and which has the smallest sample size.Data From Exercise 7.33: A B 0.0 0.1 0.2
According to a 2017 Pew Research report, 40% of millennials have a BA degree. Suppose we take a random sample of 500 millennials and find the proportion who have a BA degree.a. What value should we
According to The Washington Post, 72% of high school seniors have a driver’s license. Suppose we take a random sample of 100 high school seniors and find the proportion who have a driver’s
A large collection of one-digit random numbers should have about 50% odd and 50% even digits, because five of the ten digits are odd (1, 3, 5, 7, and 9) and five are even (0, 2, 4, 6, and 8).a. Find
Use the data given in Exercise 7.23. Make the two given tables into one table by combining men for capital punishment into one group, men opposing it into another, women for it into one group, and
To determine if patrons are satisfied with performance quality, a theater surveys patrons at an evening performance by placing a paper survey inside their programs. All patrons receive a program as
A school district conducts a survey to determine whether voters favor passing a bond to fund school renovation projects. All registered voters are called. Of those called, 15% answer the survey call.
You need to select a simple random sample of two from six friends who will participate in a survey. Assume the friends are numbered 1, 2, 3, 4, 5, and 6. Use technology to select your random sample.
Suppose you want to estimate the mean grade point average (GPA) of all students at your school. You set up a table in the library asking for volunteers to tell you their GPAs. Do you think you would
The Centers for Disease Control and Prevention (CDC) conducts an annual Youth Risk Behavior Survey, surveying over 15,000 high school students. The 2015 survey reported that, while cigarette use
Chapman University conducts an annual Survey of American Fears. One of the objectives of this survey is to collect annual data on the fears, worries, and concerns of Americans. In 2017 the survey
The city of Chicago provides an open data set of the number of WiFi sessions at all of its public libraries. For 2014, there were an average of 451,846.9 WiFi sessions per month at all Chicago public
The city of San Francisco provides an open data set of commercial building energy use. Each row of the data set represents a commercial building. A sample of 100 buildings from the data set had a
The standard deviation of all professional NBA basketball players is 29.9 pounds. A sample of 50 professional basketball players has a standard deviation of 26.7 pounds. which number is s, and which
μ vs. x̅ The mean weight of all professional NBA basketball players is 218.8 pounds. A sample of 50 professional basketball players has a mean weight of 217.6 pounds. Which number is m, and which
σ vs. s Two symbols are used for the standard deviation: σ and s.a. Which represents a parameter, and which represents a statistic?b. To estimate the commute time for all students at a college, 100
x vs. μ Two symbols are used for the mean: μ and x̅.a. Which represents a parameter, and which a statistic?b. In determining the mean age of all students at your school, you survey 30 students and
The website scholarshipstats.com collected data on all 5341 NCAA basketball players for the 2017 season and found a mean height of 77 inches. Is the number 77 a parameter or a statistic? Also
Bob Ross hosted a weekly television show, The Joy of Painting, on PBS in which he taught viewers how to paint. During each episode, he produced a complete painting while teaching viewers how they
In 2017 Pew Research Center polled 3930 adults in the United States and found that 43% reported playing video games often on some kind of electronic device.a. Identify the population and the
In 2017 the Gallup poll surveyed 1021 adults in the United States and found that 57% supported a ban on smoking in public places.a. Identify the population and the sample.b. What is the parameter of
Support for the legalization of marijuana has continued to grow among Americans. A 2017 Gallup poll found that 64% of Americans now say that marijuana use should be legal. Suppose a random sample of
According to a Pew poll, 67% of Americans believe that jury duty is part of good citizenship. Suppose 500 Americans are randomly selected.a. Find the probability that more than half believe that jury
According to the Pew Research Center, 73% of Americans have read at least one book during the past year. Suppose 200 Americans are randomly selected.a. Find the probability that more than 150 have
Voice-controlled video assistants are being incorporated into a wide variety of consumer products, including smartphones, tablets, and stand-alone devices such as the Amazon Echo or Google Home. A
According to a 2017 Gallup poll, 17% of Americans report they rarely feel stressed. Suppose 80 Americans are randomly sampled. Find the probability of the following:a. Exactly 15 rarely feel
According to a 2017 Gallup poll, 44% of Americans report they frequently feel stressed. Suppose 200 Americans are randomly sampled. Find the probability of the following:a. Fewer than 80 frequently
The distribution of spring high temperatures in Los Angeles is approximately Normal, with a mean of 75 degrees and a standard deviation of 2.5 degrees.a. What is the probability that the high
Systolic blood pressures are approximately Normal with a mean of 120 and a standard deviation of 8.a. What percentage of people have a systolic blood pressure above 130?b. What is the range of
See problem 6.89 for information about USMLE scores.a. What USMLE score would correspond with a z-score of -2?b. What USMLE score corresponds with a z-score of 1?c. Find the z-score that corresponds
Medical school graduates who want to become doctors must pass the U.S. Medical Licensing Exam (USMLE). Scores on this exam are approximately Normal with a mean of 225 and a standard deviation of 15.
In a game of chance, players draw one cube out of a bag containing 3 red cubes, 2 white cubes, and 1 blue cube. The player wins $5 if a blue cube is drawn, the player loses $2 if a white cube is
Determine whether each of the following variables would best be modeled as continuous or discrete:a. Number of girls in a familyb. Height of a treec. Commute timed. Concert attendance
Professional basketball LeBron James is a 74% free-throw shooter. Assume that free throw shots are independent. Suppose, over the course of a season, James attempts 600 free throws.a. Find the mean
According to the Pew Research Center, 53% of millennials (those born between 1981 and 1997) reported using a library or bookmobile within the last year. Suppose that a random sample of 200
According to a study by the Colorado Department of Transportation, 25% of Colorado drivers admit to using their cell phones to send texts while driving. Suppose two Colorado drivers are randomly
According to a report by the American Academy of Orthopedic Surgeons, 29% of pedestrians admit to texting while walking. Suppose two pedestrians are randomly selected.a. If the pedestrian texts while
A 2017 Pew Research Center report on drones found that only 24% of Americans felt that drones should be allowed at events, like concerts or rallies. Suppose 100 Americans are randomly selected.a.
The use of drones, aircraft without onboard human pilots, is becoming more prevalent in the United States. According to a 2017 Pew Research Center report, 59% of American had seen a drone in action.
According to the Centers of Disease Control and Prevention, 44% of U.S. households still had landline phone service. Suppose a random sample of 60 U.S. households is taken.a. Find the probability
According to the Centers of Disease Control and Prevention, 52% of U.S. households had no landline and only had cell phone service. Suppose a random sample of 40 U.S. households is taken.a. Find the
According to a survey conducted by OnePoll, a marketing research company, 10% of Americans have never traveled outside their home state. Assume this percentage is accurate. Suppose a random sample of
According to data from the U.S. State Department, the percentage of Americans who have a passport has risen dramatically. In 2007, only 27% of Americans had a passport; in 2017 that percentage had
According to the American Veterinary Medical Association, 30% of Americans own a cat.a. Find the probability that exactly 2 out of 8 randomly selected Americans own a cat.b. In a random sample of 8
According to the American Veterinary Medical Association, 36% of Americans own a dog.a. Find the probability that exactly 4 out of 10 randomly selected Americans own a dog.b. In a random sample of 10
For each situation, identify the sample size n, the probability of a success p, and the number of success x. When asked for the probability, state the answer in the form b(n, p, x). There is no need
For each situation, identify the sample size n, the probability of a success p, and the number of success x. When asked for the probability, state the answer in the form b(n, p, x). There is no need
Alaska Airlines has an on-time arrival rate of 88%. Assume that in one day, this airline has 1200 flights. Suppose we pick one day in December and find the number of on time Alaska Airline arrivals.
Professional basketball player Draymond Green has a free throw success rate of 70%. Suppose Green takes as many free throws as he can in one minute. Why would it be inappropriate to use the binomial
A die is rolled 5 times, and the number of spots for each roll is recorded. Explain why this is not a binomial experiment. Name a condition for use of the binomial model that is not met.
According to the National Health Center, the heights of 5 year-old boys are Normally distributed with a mean of 43 inches and a standard deviation of 1.5 inches.a. In which percentile is a 5-year-old
The distribution of grade point averages GPAs for medical school applicants in 2017 were approximately Normal, with a mean of 3.56 and a standard deviation of 0.34. Suppose a medical school will only
Scores on the 2017 MCAT, an exam required for all medical school applicants, were approximately Normal with a mean score of 505 and a standard deviation of 9.4.a. Suppose an applicant had an MCAT
The weight of newborn hippopotami is approximately Normal, with a mean of 88 pounds and a standard deviation of 10 pounds.a. What is the probability that a newborn hippo weighs between 90 and 110
The length of gestation for hippopotami is approximately Normal, with a mean of 270 days and a standard deviation of 7 days.a. What percentage of hippos have a gestation period less than 260 days?b.
In a standard Normal distribution, if the area to the left of a z-score is about 0.1000, what is the approximate z-score?
The Normal model N(150, 10) describes the distribution of scores on the LSAT, a standardized test required by most law schools. Which of the following questions asks for a probability, and which asks
The Normal model N(69, 3) describes the distribution of male heights in the United States. Which of the following questions asks for a probability, and which asks for a measurement? Identify the type
The average winter daily temperature in Chicago has a distribution that is approximately Normal, with a mean of 28 degrees and a standard deviation of 8 degrees. What percentage of winter days in
According to Anthropometric Survey data, the distribution of arm spans for females is approximately Normal with a mean of 65.4 inches and a standard deviation of 3.2 inches.a. What percentage of
According to Anthropometric Survey data, the distribution of arm spans for males is approximately Normal with a mean of 71.4 inches and a standard deviation of 3.3 inches.a. What percentage of men
According to the 2017 SAT Suite of Assessments Annual Report, the average ERW (English, Reading, Writing) SAT score in Florida was 520. Assume the scores are Normally distributed with a standard
According to the 2017 SAT Suite of Assessments Annual Report, the average SAT math score for students in Illinois was 556. Assume the scores are Normally distributed with a standard deviation of 100.
The distribution of red blood cell counts is different for men and women. For both, the distribution is approximately Normal. For men, the middle 95% range from 4.5 to 5.7 million cells per
The distribution of white blood cell count per cubic millimeter of whole blood is approximately Normal with mean 7500 and standard deviation 1750 for healthy patients. Use technology or a table to
According to National Vital Statistics, the average length of a newborn baby is 19.5 inches with a standard deviation of 0.9 inches. The distribution of lengths is approximately Normal. Use
According to the British Medical Journal, the distribution of weights of newborn babies is approximately Normal, with a mean of 3390 grams and a standard deviation of 550 grams. Use a technology or a
Suppose a shoe store stocks shoes in women’s sizes 5 though 9. These shoes will fit women with feet that are 21.6 through 25 centimeters long. What percentage of women will be able to find shoes
Suppose a shoe store stocks shoes in men’s sizes 7 through 12. These shoes will fit men with feet that are 24.6 to 28.8 centimeters long. What percentage of boys aged 16 to 17 will not be able to
According to the Digital Human Modeling Project, the distribution of foot lengths of women is approximately Normal with a mean of 23.1 centimeters and a standard deviation of 1.1 centimeters. In the
According to the Digital Human Modeling Project, the distribution of foot lengths of 16- to 17-year-old boys is approximately Normal with a mean of 25.2 centimeters and a standard deviation of 1.2

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