New Semester Started Get 50% OFF Study Help! --h --m --s Claim Now

Question Answers

Textbooks

Find textbooks, questions and answers

Oops, something went wrong!

Change your search query and then try again

Result Not Found

Books FREE
Study Help
Tutors
AI Study Planner NEW
Sell Books

Search
Sign In
Register

study help
business
bayesian statistics an introduction

Statistics Through Applications 2nd Edition Daren S Starnes, David S Moore, Dan Yates - Solutions

Are we getting smarter? When the Stanford-Binet “IQ test” came into use in 1932, it was adjusted so that scores for each age group of children followed roughly the Normal distribution with mean 100 and standard deviation 15. Th e test is readjusted from time to time to keep the mean at 100. If
NCAA rules for athletes The National Collegiate Athletic Association(NCAA) requires Division I athletes to score at least 820 on the combined Mathematics and Critical Reading parts of the SAT exam in order to compete in their first college year. (Higher scores are required for students with poor
More Table A practice, II Use Table A to fi nd the value z from a standard Normal distribution that satisfi es each of the following conditions. In each case, sketch a standard Normal curve with your value of z marked on the axis. Use an applet or your calculator to check your answers.(a) Th e
More Table A practice, I Use Table A to fi nd the proportion of observations from a standard Normal distribution that satisfi es each of the following statements.In each case, sketch a standard Normal curve and shade the area under the curve that is the answer to the question. Use an applet or your
Normal curve properties, II Explain why the point that is one standard deviation below the mean in a Normal distribution is always the 16th percentile. Explain why the point that is two standard deviations above the mean is the 97.5th percentile.
Normal curve properties, I Figure 3.26 is a Normal density curve. Estimate the mean and the standard deviation of this distribution.
Heights of young women Th e distribution of the heights of young women aged 18 to 24 is approximately Normal with mean 65 inches and standard deviation 2.5 inches. Sketch a picture of a Normal curve and then use the 68–95–99.7 rule to show what the rule states about these women’s heights.
Brush your teeth Th e amount of time Ricardo spends brushing his teeth follows a Normal distribution with unknown mean m and standard deviation s 5 20 seconds. Ricardo spends less than 60 seconds brushing his teeth about 40% of the time. Use this information to determine the mean of this
Potatoes Bags of potatoes in a shipment averaged 10 pounds with a standard deviation of 0.5 pounds. A histogram of these weights followed a Normal curve quite closely.(a) What percent of the bags weighed less than 10.25 pounds? Show your work.(b) What percent weighed between 9.5 and 10.25 pounds?
SAT scores, II Refer to the previous exercise.(a) Find the 85th percentile of the SAT Math score distribution for males. Show your work.(b) To what percentile in the female score distribution does your answer to(a) correspond? Show your work.
SAT scores, I Th e average performance of females on the SAT, especially the Math section, is lower than that of males. Th e reasons for this gender gap are controversial. In 2007, female scores on the SAT Math test followed a Normal distribution with mean 500 and standard deviation 111. Male
High IQ scores Scores on the Wechsler Adult Intelligence Scale for 20- to 34-year-olds are approximately Normally distributed with mean 110 and standard deviation 25. How high must a person score to be in the top 25% of all scores?Show your work.
Tiger prowls Aft er hitting plenty of balls on the practice range, Tiger Woods heads out to the fi rst tee to begin a golf tournament. A large creek crosses the fairway 317 yards from the tee. Assume that the distance traveled by Tiger’s ball follows a Normal distribution with m 304 yards and s
Working backward, II(a) Th e 63rd percentile of the standard Normal distribution.(b) 75% of all observations are greater than z.For Exercises 3.31 and 3.32, use Table A to fi nd the value z from the standard Normal distribution that satisfi es each of the following conditions. (Use the value of z
Working backward, I(a) Th e 20th percentile of the standard Normal distribution.(b) 45% of all observations are greater than z.For Exercises 3.31 and 3.32, use Table A to fi nd the value z from the standard Normal distribution that satisfi es each of the following conditions. (Use the value of z
Table A practice, IV(a) z is between 22.05 and 0.78 (b) z is between 21.11 and 20.32 For Exercises 3.27 to 3.30, use Table A to fi nd the proportion of observations from the standard Normal distribution that satisfi es each of the following statements.In each case, sketch a standard Normal curve
Table A practice, III(a) z is between 21.33 and 1.65 (b) z is between 0.50 and 1.79 For Exercises 3.27 to 3.30, use Table A to fi nd the proportion of observations from the standard Normal distribution that satisfi es each of the following statements.In each case, sketch a standard Normal curve and
Table A practice, II(a) z is less than 21.58 (b) z is greater than 1.58(c) z is greater than 20.46 (d) z is less than 0.93 For Exercises 3.27 to 3.30, use Table A to fi nd the proportion of observations from the standard Normal distribution that satisfi es each of the following statements.In each
Table A practice, I(a) z is less than 20.37 (b) z is greater than 20.37(c) z is less than 2.15 (d) z is greater than 2.15 For Exercises 3.27 to 3.30, use Table A to fi nd the proportion of observations from the standard Normal distribution that satisfi es each of the following statements.In each
Eggs A truck is loaded with cartons of eggs that weigh an average of 2 pounds each with a standard deviation of 0.1 pound. A histogram of these weights looks very much like a Normal distribution. Use the 68–95–99.7 rule to answer the following questions.(a) What percent of the cartons weigh
Horse pregnancies Bigger animals tend to carry their young longer before birth. Th e length of horse pregnancies from conception to birth varies according to a roughly Normal distribution with mean 336 days and standard deviation 3 days.Use the 68–95–99.7 rule to answer the following
A Normal curve Estimate the mean and standard deviation of the Normal curve in Figure 3.16.
IQ test scores, III What percent of all students have IQ scores of 144 or higher? Explain. None of the 74 students in our sample school had scores this high. Are you surprised at this?Why?
IQ test scores, II What percent of IQ scores for all rural Midwest seventh-graders are greater than 100? Explain. How does this compare with the percent in our sample?
IQ test scores, I Between what values do the IQ scores of the middle 95% of all rural Midwest seventh-graders lie? Explain.
Is Miranda taller? Miranda is 16 years old and 170 cm tall.(a) Find the z-score corresponding to Miranda’s height. Explain what this value means.(b) Miranda’s height puts her at the 88th percentile among 16-year-old females.Explain what this means to someone who knows no statistics.(c) Refer to
Is Paul tall? Paul is 15 years old and 175 cm tall.(a) Find the z-score corresponding to Paul’s height. Explain what this value means.(b) Paul’s height puts him at the 75th percentile among 15-year-old males. Explain what this means to someone who knows no statistics.
Female heights Consider the height distribution for 16-year-old females.(a) Find its mean and standard deviation. Show your method clearly.(b) What height would correspond to a z-score of 1.5? Show your work.
Male heights Consider the height distribution for 15-year-old males.(a) Find its mean and standard deviation. Show your method clearly.(b) What height would correspond to a z-score of 2.5? Show your work.
Unemployment in the states, II Refer to the previous exercise. Th e December 2000 unemployment rates for the 50 states had a symmetric, singlepeaked distribution with a mean of 3.47% and a standard deviation of about 1%. Th e unemployment rate for Illinois that month was 4.5%. Th ere were 42 states
Unemployment in the states, I Each month the Bureau of Labor Statistics announces the unemployment rate for the previous month. Unemployment rates are economically important and politically sensitive. Unemployment may vary greatly among the states because types of work are unevenly distributed
Cholesterol: good or bad? Martin came home very excited aft er a visit to his doctor. He announced proudly to his wife, “My doctor says my cholesterol level is at the 90th percentile among men like me. Th at means I’m better off than about 90% of similar men.” How should his wife, who is a
Finding means and medians Figure 3.11 (on the next page) displays three density curves, each with three points indicated. At which of these points on each curve do the mean and the median fall? ABC (a) ABC (b) Figure 3.11 Three density curves: can you locate the mean and median? AB C
Percentiles and density curves Joey told his dad that he scored at the 98th percentile on a national standardized test. Th e scores on this test are approximately Normally distributed. Sketch a Normal density curve and show the approximate location of Joey’s score in the distribution.
Mean and median Figure 3.10 (on the next page) shows two density curves. Briefl y describe the overall shape of each distribution. Two points are marked on each curve to help you locate the mean and the median. For each curve, give the letter that corresponds to (i) the median and (ii) the mean.
From histogram to density curve, II Copy the distribution in Figure 3.9 onto your paper. Th en sketch a smooth curve that describes the distribution well.Mark your best guess for the mean and median of the distribution.
From histogram to density curve, I Copy the distribution in Figure 3.8 onto your paper. Th en sketch a smooth curve that describes the distribution well. Mark your best guess for the mean and median of the distribution.
Another uniform distribution Refer to the previous exercise. Now let’s consider a uniform distribution over the interval from 0 to 2.(a) Sketch a graph of the density curve. What is the height of the curve? Why?(b) What percent of the observations lie between 1 and 1.4? Explain.(c) Find the
A uniform distribution Figure 3.7 (on the facing page) shows the density curve for a uniform distribution. Th is curve has height 1 over the interval from 0 to 1 and is zero outside that range.Use this density curve to answer the following questions.(a) Why is the height of the curve equal to 1?(b)
Baseball salaries, II Did Ryan Madson have a high salary or a low salary compared with the rest of the team? Justify your answer using Madson’s percentile and z-score.
Baseball salaries, I Brad Lidge played a crucial role as the Phillies’ “closer”;that is, he pitched the end of many games throughout the season.(a) Find the percentile corresponding to Lidge’s salary. Explain what this value means.(b) Find the z-score corresponding to L Elsa/Getty Images
Comparing bone density Refer to the previous exercise. One of Francine’s friends, Louise, has the bone density in her hip measured using DEXA. Louise is 35 years old. Her bone density is also reported as 948 g/cm2, but her standardized score is z 5 0.50. Th e mean bone density in the hip for the
Measuring bone density Individuals with low bone density have a high risk of broken bones (fractures). Physicians who are concerned about low bone density (osteoporosis) in patients can refer them for specialized testing.Currently, the most common method for testing bone density is dual-energy
Comparing performance: percentiles Peter is a star runner on the track team, and Molly is one of the best sprinters on the swim team. Both athletes qualify for the league championship meet based on their performance during the regular season.(a) In the track playoff s, Peter records a time that
Interpreting percentiles(a) Mrs. Munson is concerned about how her daughter’s height and weight compare with those of other girls her age. She uses an online calculator to determine that her daughter is at the 87th percentile for weight and the 67th percentile for height. Explain to Mrs. Munson
Sleep: hours or minutes? Refer to the previous exercise. Suppose the sleep increase data are converted from hours to minutes. How will this aff ect the mean, median, standard deviation, and IQR? Explain.
Getting more sleep An experiment was carried out with 10 patients to investigate the eff ectiveness of a drug that was designed to increase sleep time. Th e data below show the number of additional hours of sleep gained by each subject aft er taking the drug.30 (A negative value indicates that the
Home run king In 1927, Babe Ruth broke Major League Baseball’s singleseason home run record by hitting 60 home runs. Th e Babe’s record stood until 1961, when Roger Maris hit 61 homers in a season. Almost 40 years later, Mark McGwire(70) and Sammy Sosa (68) excited baseball fans by smashing
Are you wired? In late 2006, the Pew Internet and American Life Project conducted a telephone survey of 935 adults and their children aged 12 to 17. One question they asked was “Do you, personally, happen to have . . . a desktop computer? A cell phone? An iPod or other MP3 player? A laptop
State SAT scores Figure 2.33 (on the next page) is a histogram of the average scores on the mathematics part of the SAT exam for students in the 50 states and the District of Columbia.29 Th e distinctive overall shape of this distribution implies that a single measure of center such as the mean or
We pay high interest Figure 2.32 shows a graph taken from an advertisement for an investment that promises to pay a higher interest rate than bank accounts and other competing investments. Is this graph a correct comparison of the four interest rates? Explain your answer. 6% 4%- 2% 3.5% 4.4% 5.1%
Who sells cars? Figure 2.31 is a pie chart of the percent of passenger car sales in a given year by various manufacturers.(a) Th e artist has tried to make the graph more interesting by using the wheel of a car for the “pie.” Is the graph still a correct display of the data? Explain your
Smoking-related deaths Below is a table from Smoking and Health Now, a report of the British Royal College of Physicians. It shows the number and percent of deaths among men aged 35 and over from the chief diseases related to smoking. One of the entries in the table is incorrect and an erratum slip
Be creative! Make up a list of numbers of which only 10% are above the average(that is, above the mean). What percent of the numbers in your list fall above the median?
CHANCE News wiki Th e CHANCE Web site at Dartmouth College contains lots of interesting stuff (at least if you are interested in statistics). In particular, the CHANCE News wiki at http://chance.dartmouth.edu/chancewiki features articles about published statistical results in the media, including
Poverty Th e number of Americans living below the offi cial poverty line increased from 32,476,000 to 37,276,000 in the 10 years between 1998 and 2007.What percent increase was this? You should not conclude from this that poverty grew more common in these years, however. Why not?
Online card games Figure 2.29 (on the next page) shows the number of people playing card games at the Yahoo Web site on a Sunday and on a Wednesday in the same week.(a) Explain what’s wrong with this graph.(b) Make a more appropriate graph to display these data.
We can read, but can we count? Th e Census Bureau once gave a simple test of literacy in English to a random sample of 3400 people. Th e New York Times printed some of the questions under the headline “113% of Adults in U.S. Failed Th is Test.”28 Why is the percent in the headline clearly wrong?
Deer in the suburbs Westchester County is a suburban area covering 438 square miles immediately north of New York City. A garden magazine claimed that the county is home to 800,000 deer.27 Do a calculation that shows this claim to be implausible.
Oatmeal and cholesterol Does eating Quaker Oatmeal reduce cholesterol?An advertisement included the following graph as evidence that the answer is “Yes.”(a) How is this graph misleading?(b) Make a new graph that isn’t misleading. What do you conclude about the eff ect of eating Quaker Oats on
Greeks on campus Th e question-and-answer column of a college campus newspaper was asked what percent of the campus was “Greek” (that is, members of fraternities or sororities). Th e answer given was that “the fi gures for the fall semester are approximately 13 percent for the girls and
The rise in college education The line graph on the facing page shows the rise in the percent of women 25 years old and over who have at least a bachelor’s degree. Identify at least two features of this graph that make it confusing or misleading.
Getting to school Students in a high school statistics class were given data about the primary method of transportation to school for a group of 30 students.Th ey produced the pictograph shown on the facing page.(a) How is this graph misleading?(b) Make a graph of the data that is not misleading.
Lottery ticket sales, II Refer to the previous exercise. Draw a new line graph of the data displayed in Figure 2.28 that isn’t deceptive. Describe what you see.
Lottery ticket sales, I Figure 2.28 is a line graph of the total lottery ticket sales (in millions of dollars) in the United States from 1980 to 2007. What’s wrong with this picture?
Support the court? In 2005, CNN reported the results of a survey about a Florida court’s decision to remove the feeding tube from coma patient Terry Schiavo, eff ectively ending her life. Figure 2.27 (on the next page) shows a bar graph of the data that CNN initially posted on its Web site.(a)
Th e cost of fresh oranges Figure 2.26 is a line graph of the average cost of fresh oranges each month from January 2000 to December 2008. Th ese data, from the Bureau of Labor Statistics monthly survey of retail prices, are “index numbers”rather than prices in dollars and cents. Th at is, they
I’d die without my phone! In a July 2008 survey of over 2000 U.S. teenagers by Harris Interactive, 47% said that “their social life would end or be worsened without their cell phone.”18 One survey question asked the teens how important it is for their phone to have certain features. Figure
Teacher raises, II Refer to the previous exercise.If each teacher receives a 5% raise instead of a $1000 raise, the amount of the raise will vary from $900 to$2000, depending on the present salary.(a) What will this do to the mean salary? To the median salary? Explain your answers.(b) Will a 5%
Teacher raises, I A school system employs teachers at salaries between $18,000 and $40,000. Th e teachers’ union and the school board are negotiating the form of next year’s increase in the salary scale.(a) If every teacher is given a $1000 raise, what will this do to the mean salary? To the
Phosphate levels Th e level of various substances in the blood infl uences our health. Here are measurements of the level of phosphate in the blood of a patient, in milligrams of phosphate per deciliter of blood, made on six consecutive visits to a clinic:5.6 5.2 4.6 4.9 5.7 6.4(a) Find the mean
Poverty in the eastern states Th e poverty rates for states east of the Mississippi have been divided into northern and southern states, according to the geographic divisions used by the Census Bureau.Figure 2.20 shows boxplots of the poverty rates for the states in each region. Write a few
Mean or median? You are planning a party and want to know how many cans of soda to buy. A genie off ers to tell you either the mean number of cans guests will drink or the median number of cans. Which measure of center should you ask for? Why? To make your answer concrete, suppose that there will
Which is easier—AP Calculus AB or AP Statistics? Th e table below gives the distribution of grades earned by students taking the AP Calculus AB and AP Statistics exams in 2008.15(a) Make an appropriate graphical display to compare the grade distributions for AP Calculus AB and AP Statistics.(b)
Electoral votes, II Refer to the previous exercise. Which measure of center and spread would you use to summarize the distribution in Figure 2.19: (i) the mean and standard deviation or (ii) the median and IQR? Justify your answer.
Electoral votes, I To become president of the United States, a candidate does not have to receive a majority of the popular vote. Th e candidate does, however, have to win a majority of the 538 electoral votes that are cast in the Electoral College. Figure 2.19 is a stemplot of the number of
Tuna from where? Does mercury content in canned tuna diff er by country of origin? Th e Fathom boxplots and summary chart that follow provide information to help you answer this question. Write a few sentences comparing the distributions of mercury concentration based on country of origin. Mercury
Cool car colors Table 2.8 gives information about the most popular colors of vehicles purchased in 2007. Make a bar graph that compares the color distributions for full size/intermediate cars and SUVs/trucks. Describe any similarities and diff erences between the two distributions.
Tall or short, II Refer to the previous exercise. Mr. Walker converts his students’ original heights from inches to feet.(a) Find the mean and median of the students’ heights in feet. Show your work.(b) Find the standard deviation and IQR of the students’ heights in feet. Show your work.
Tall or short, I Mr. Walker measures the heights (in inches) of the students in one of his classes. He uses a computer to calculate the following numerical summaries:Mean Std. dev. Min. Q1 Med. Q3 Max.69.188 3.20 61.5 67.75 69.5 71 74.5 Next, Mr. Walker has his entire class stand on their chairs,
Domain names When it comes to Internet domain names, is shorter better? According to one ranking of Web sites in 2008, the top 8 sites (by number of “hits”) were yahoo.com, google.com, youtube.com, live.com, msn.com, myspace.com, wikipedia.org, and facebook.com. Th ese familiar sites certainly
Music CDs How many music CDs do students own? Th e 24 members of a college statistics class provided data in response to this question.14 Figure 2.17 is a dotplot of the data. Which would better summarize the center and spread of the distribution: (i) the mean and standard deviation or (ii) the
Properties of the standard deviation(a) Juan says that, if the standard deviation of a list is zero, then all the numbers on the list are the same. Is Juan correct? Explain your answer.(b) Letishia alleges that, if the means and standard deviations of two diff erent lists of numbers are the same,
A matchup Match the summary statistics with the histograms. Explain how you made your decision.(a) mean = 6.6, median = 6.8, standard deviation = 1.3, variable _____________.(b) mean = 6.6, median = 6.0, standard deviation = 8.65, variable_____________.(c) mean = 6.6, median = 3.75, standard
Feeling sleepy? Th e fi rst four students to arrive for a fi rst-period statistics class were asked how much sleep (to the nearest hour) they got last night. Th eir responses were 7, 7, 9, and 9.(a) Use the formula to calculate the mean. Interpret this value.(b) Use the method in Example 2.15 to
Mean income You read that the mean income of U.S. households in 2007 was $67,609. Recall from Exercise 2.27 (page 65) that the median U.S. household income in 2007 was $50,233. Explain why the mean household income is so much higher than the median household income.
Metabolism, II Refer to the previous exercise.(a) Use the method in Example 2.15 to calculate the deviation of each observation from the mean. Show that the sum of the deviations is 0.(b) Calculate the standard deviation. Show your work.
Metabolism, I A person’s metabolic rate is the rate at which the body consumes energy. Metabolic rate is important in studies of weight gain, dieting, and exercise. Here are the metabolic rates of seven men who took part in a study of dieting. (Th e units are calories per 24 hours. Th ese are the
Texting or calling, II Refer to the previous exercise.(a) Do Mr. Williams’s students seem to prefer texting or talking on the phone?Give appropriate evidence to support your answer.(b) Can we draw any conclusion about the preferences of all students in the school based on the data from Mr.
Texting or calling, I After hearing about the text message study of Example 2.10, Mr. Williams collects data from each student in his math class on the number of cell phone texts and calls sent or received in the past 24 hours. Figure 2.14 is a boxplot of the difference(texts calls) in the number
Phone calls, II Refer to the previous exercise. Make a boxplot of the phone call data from Mrs. Krebs’s class.How would you describe the distribution of the variable“number of phone calls made or received in the past 24 hours”?
Phone calls, I After hearing about the text message study of Example 2.10, Mrs. Krebs asked the students in her statistics class how many phone calls they had made or received in the past 24 hours. Here are their responses:3 0 12 10 8 4 2 7 10 11 6 7 0 35 12 3 10 2 7 9 15 5 14 15 6(a) Find the
Acing the fi rst test Here are the scores of Mrs. Liao’s students on their fi rst statistics test:93 93 87.5 91 94.5 72 96 95 93.5 93.5 73 82 45 88 80 86 85.5 87.5 81 78 86 89 92 91 98 85 82.5 88 94.5 43(a) Find the median. Explain what this number means in this setting.(b) Find the quartiles and
Median income You read that the median income of U.S. households in 2007 was $50,233. Explain in plain words what “the median income” is.
How tall are you? Here are the heights (in centimeters) of the 50 randomly selected Canadian students who participated in CensusAtSchool in 2007–2008.166.5 170 178 163 150.5 169 173 169 171 166 190 183 178 161 171 170 191 168.5 178.5 173 175 160.5 166 164 163 174 160 174 182 167 166 170 170 181
Who’s left-handed? Students were asked, “Are you right-handed, lefthanded or ambidextrous?” The responses of the 50 randomly selected Canadian students are shown below (R right-handed; L left-handed;A ambidextrous).R R R R R R R R R R R L R R R R R R R R R R R R R R R A R R R R A R R L
Travel time Th e dotplot on the facing page displays data on students’ responses to the question “How long does it usually take you to travel to school?”(a) Make a well-labeled histogram of the data.(b) Describe the shape, center, and spread of the distribution. Are there any outliers? 0 20
Let’s chat Th e bar graph on the left displays data on students’ responses to the question “Which of these methods do you most oft en use to communicate with your friends?”(a) Would it be appropriate to make a pie chart for these data? If so, do it. If not, explain why not.(b) Summarize
Skewed left(a) Sketch a histogram for a distribution that is skewed to the left .(b) Suppose that you and your friends emptied your pockets of coins and recorded the year marked on each coin. Th e distribution of dates would be skewed to the left . Explain why.
Low birth weights Figure 2.12 (on the next page) shows the distribution of percent of low birth weights for the 26 states east of the Mississippi.10 Notice that the vertical scale in Figure 2.12(a) is the number of states in each class. In Figure 2.12(b), we have calculated and displayed the

Showing 1500 - 1600 of 2867

First
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
Last

Step by Step Answers

Services

Sitemap
Fun
Definitions
Become Tutor
Used Textbooks
Study Help Categories
Recent Questions
Expert Questions
Campus Wear
Sell Your Books

Company Info

Security
Copyrights
Privacy Policy
Terms & Conditions
SolutionInn Fee
Scholarship
Online Quiz
Give Feedback, Get Rewards

Get In Touch

About Us
Contact Us
Career
Jobs
FAQ
Student Discount
Campus Ambassador

Secure Payment

Download Our App

© 2026 SolutionInn. All Rights Reserved