Solution Manual for Statistics, Updated Edition, 13th Edition

Preview (16 of 555 Pages)

100%

Solution Manual for Statistics, Updated Edition, 13th Edition - Page 1 preview image

Loading page ...

Statistics, Data, and Statistical Thinking1Statistics, Data,and Statistical Thinking1.2Descriptive statistics utilizes numerical and graphical methods to look for patterns, tosummarize, and to present the information in a set of data. Inferential statistics utilizessample data to make estimates, decisions, predictions, or other generalizations about a largerset of data.1.4The first major method of collecting data is from a published source. These data have alreadybeen collected by someone else and is available in a published source. The second method ofcollecting data is from a designed experiment. These data are collected by a researcher whoexerts strict control over the experimental units in a study. These data are measured directlyfrom the experimental units. The third method of collecting data is from a survey. Thesedata are collected by a researcher asking a group of people one or more questions. Again,these data are collected directly from the experimental units or people. The final method ofcollecting data is observationally. These data are collected directly from experimental unitsby simply observing the experimental units in their natural environment and recording thevalues of the desired characteristics.1.6A population is a set of existing units such as people, objects, transactions, or events. Avariable is a characteristic or property of an individual population unit such as height of aperson, time of a reflex, amount of a transaction, etc.1.8A representative sample is a sample that exhibits characteristics similar to those possessed bythe target population. A representative sample is essential if inferential statistics is to beapplied. If a sample does not possess the same characteristics as the target population, thenany inferences made using the sample will be unreliable.1.10Statistical thinking involves applying rational thought processes to critically assess data andinferences made from the data. It involves not taking all data and inferences presented at facevalue, but rather making sure the inferences and data are valid.1.12a.High school GPA is a number usually between 0.0 and 4.0. Therefore, it is quantitative.b.High school class rank is a number: 1st, 2nd, 3rd, etc. Therefore, it is quantitative.c.The scores on the SAT's are numbers between 200 and 800. Therefore, it isquantitative.d.Gender is either male or female. Therefore, it is qualitative.e.Parent's income is a number: $25,000, $45,000, etc. Therefore, it is quantitative.f.Age is a number: 17, 18, etc. Therefore, it is quantitative.1.14a.The experimental unit for this experiment is a drafted NFL quarterback.b.Draft position is one of three categories. Therefore, it is a qualitative variable. NFLwinning ratio is a number. Therefore, it is a quantitative variable. QB production scoreis a number. Therefore, it is a quantitative variable.Chapter1

Solution Manual for Statistics, Updated Edition, 13th Edition - Page 2 preview image

Loading page ...

Solution Manual for Statistics, Updated Edition, 13th Edition - Page 3 preview image

Loading page ...

2Chapter 1c.Because all quarterbacks drafted over a 38-year period were used, the application of thisstudy is descriptive statistics.1.16a.The variable “difference between before and after sprint times” is measured in seconds.Thus, it is quantitative. The variable “improvement” is measured as one of threecategories. Thus, it is qualitative.b.The data set is a sample. It contains observations from only 14 of all high school footballplayers.1.18a.The population of interest is all the students in the class. The variable of interest is theGPA of a student in the class.b.Since GPA is measured on a numerical scale, it is quantitative.c.Since the population of interest is all the students in the class and you obtained the GPAof every member of the class, this set of data would be a census.d.Assuming the class had more than 10 students in it, the set of 10 GPAs would representa sample. The set of ten students is only a subset of the entire class.e.This average would have 100% reliability as an "estimate" of the class average, since itis the average of interest.f.The average GPA of 10 members of the class will not necessarily be the same as theaverage GPA of the entire class. The reliability of the estimate will depend on howlarge the class is and how representative the sample is of the entire population.g.In order for the sample to be a random sample, every member of the class must have anequal1.20a.Flight capability can have only 2 possible outcomes: volant or flightless. Thus, it isqualitative.b.Habitat type can have only 3 possible outcomes: aquatic, ground terrestrial, or aerialterrestrial. Thus, it is qualitative.c.Nesting site can have only 4 possible outcomes: ground, cavity within ground, tree, orcavity above ground. Thus, it is qualitative.d.Nest density can have only 2 possible outcomes: high or low. Thus, it is qualitative.e.Diet can have only 4 possible outcomes: fish, vertebrates, vegetables, or invertebrates.Thus, it is qualitative.f.Body mass is measured in grams, a meaningful number. Thus, it is quantitative.g.Egg length is measured in millimeters, a meaningful number. Thus, it is quantitative.h.Extinct status can have only 3 possible outcomes: extinct, absent from island, or present.Thus, it is qualitative.

Solution Manual for Statistics, Updated Edition, 13th Edition - Page 4 preview image

Loading page ...

Statistics, Data, and Statistical Thinking31.22a.The population of interest to CSI is all computer security personnel at all U.S.corporations and government agencies.b.The data collection method is a survey. A survey was sent to 5,412 firms with 351 firmsresponding.c.The variable collected was whether or not the respondents admitted unauthorized use ofcomputer systems at their firms during the year. Since the response to the questions waseither “yes” or “no”, this variable is qualitative.d.In the sample 41% of the respondents admitted unauthorized use of computer systems attheir firms during the year. If there is no nonresponse bias, then we can conclude that41% of all firms would admit to unauthorized use of computer systems at their firmsduring the year.1.24The following variables would be qualitative because the response would be a category:country of operator/owner, primary use, and class of orbit. The following variables would bequantitative because the response would be a number: Longitudinal position, apogee, launchmass, usable electric power, and expected lifetime.1.26a.The population of interest is all senior managers at CPA firms.b.The data collection method used is a survey.c.Because only 992 of the 23,500 surveys sent out were returned and useable, there may bea problem with selection bias and/or nonresponse bias.d.The validity of the inferences drawn from the study would be suspect. The inferenceswould only be valid if the 992 returned surveys were indeed, representative of the entirepopulation. This is very unlikely.1.28a.The experimental unit for this study is a single-family residential property in Arlington,Texas.b.The variables measured were the Zillow estimated value and the actual sale price. Bothare quantitative variables.c.If the population was described as all single-family residential properties in Arlington,Texas that sold within a given time period, then these 2,045 single-family residentialproperties could be the population if these were the only single-family residentialproperty sales in Arlington, Texas in that time period.d.The population could be all single-family residential properties sold in Arlington, Texasin a given time period and these 2,045 single-family residential properties did not includeall the properties sold.e.No. The single-family residential properties sold in Arlington, Texas probably are notsimilar to all single-family residential properties sold in the United States. Single-familyresidential properties sold in Arlington, Texas are not similar to single-family residentialproperties sold in places like New York City or San Francisco, California.

Solution Manual for Statistics, Updated Edition, 13th Edition - Page 5 preview image

Loading page ...

4Chapter 11.30a.The population of interest is the set of all adults living in Tennessee. The sample ofinterest is the set of 575 people selected from Tennessee.b.The data collection method used was a survey. A random-digit telephone dialingprocedure was used to collect the sample. Since some people do not own phones, thiswould not be a random sample. Everyone in the state of Tennessee would not have anequal chance of being selected. Those without telephones would tend to be theundereducated. Thus, there could be potential biases in the data.c.The two variables identified in this problem are the number of years of education and theinsomnia status of each subject. The number of years of education is quantitative and theinsomnia status is qualitative.d.The researchers inferred that the fewer the years of education, the more likely the personwas to have chronic insomnia.1.32a.The experimental units of this study were people who used a popular website for engagedcouples.b.The variables of interest are the engagement ring price and the level of appreciation ofthe recipient.c.The population of interest were all those people on the popular website for engagedcouples with “average” American names.d.This sample of 33 respondents is probably not representative of the population. Thosewho decided to respond to the online survey self-selected themselves. They were notrandomly selected. Generally speaking, those people who choose to respond to a surveyhave very strong feelings and are not representative of the entire population.e.Answers will vary. Enter the numbers 1-50 in the first column of Minitab. Now, applythe random number generator of Minitab, requesting that 25 individuals be selectedwithout replacement. The sample generated include individuals 1, 3, 6, 7, 9, 10, 11, 12,13, 17, 18, 22, 24, 25, 27, 28, 30, 31, 32, 36, 37, 46, 47, 48, 50. These individuals wouldbe placed in the gift-receiver role and the remaining individuals would be placed in thegift-giver role.1.34a.In Method 1, the researchers controlled which hot spots received the new program(through random assignment) and which did not. Therefore, a designed experiment wasused to collect data in Method 1.b.In Method 2, the researchers first divided the 56 hot spots into 4 groups based on thelevel of drug crimes. The researchers then controlled which hot spots received the newprogram (through random assignment) and which did not in each of the 4 groups.Therefore, a designed experiment was also used to collect data in Method 2.c.This would be an application of inferential statistics because not all hot spots in JerseyCity were used in the study. Only a sample of 56 hot spots was used.

Solution Manual for Statistics, Updated Edition, 13th Edition - Page 6 preview image

Loading page ...

Statistics, Data, and Statistical Thinking5d.Method 2 would be recommended. By creating 4 groups where the crime rate withineach group is similar, we can control for a known source of variation. Within eachgroup, we can then see how the new program compares to no program.1.36a.Although eating oat bran can reduce cholesterol, oat bran must be the only thing eaten.Reporting that eating oat bran is an easy and cheap way to lower your cholesterol impliesthat if you add oat bran to your diet, you can reduce your cholesterol, which may not bethe case at all.b.One would need to collect data on a sample of women who gave birth to babies with birthdefects. Then, each woman in the study would also be asked whether she was a victim ofdomestic violence while pregnant or not. The data collection method for this studywould be an observational study. Specifically, one would use a survey to collect the data.c.In this study, only the results of the most positive response were reported. Not that manyhigh school girls would ‘Always’ be happy with the way they were. To be morerepresentative of those who are happy with the way they were, one should combine theresults of those who responded ‘Always true’, ‘Sort of true’, and ‘Sometimes true’.

Solution Manual for Statistics, Updated Edition, 13th Edition - Page 7 preview image

Loading page ...

6Chapter 2Methods for DescribingSets of Data2.2In a bar graph, a bar or rectangle is drawn above each class of the qualitative variablecorresponding to the class frequency or class relative frequency. In a pie chart, each slice ofthe pie corresponds to the relative frequency of a class of the qualitative variable.2.4First, we find the frequency of the grade A. The sum of the frequencies for all 5 grades mustbe 200. Therefore, subtract the sum of the frequencies of the other 4 grades from 200. Thefrequency for grade A is:200(36 + 90 + 30 + 28) = 200184 = 16To find the relative frequency for each grade, divide the frequency by the total sample size,200. The relative frequency for the grade B is 36/200 = .18. The rest of the relativefrequencies are found in a similar manner and appear in the table:Grade on Statistics ExamFrequencyRelative FrequencyA: 9010016.08B: 808936.18C: 657990.45D: 506430.15F: Below 5028.14Total2001.002.6a.The graph shown is a pie chart.b.The qualitative variable described in the graph is opinion on library importance.c.The most common opinion is more important, with 46.0% of the responders indicatingthat they think libraries have become more important.d.Using MINITAB, the Pareto diagram is:Of those who responded to the question, almost half (46%) believe that libraries havebecome more important to their community. Only 18% believe that libraries havebecome less important.Chapter2LessSameMore50403020100ImportancePercentChart of Percent

Solution Manual for Statistics, Updated Edition, 13th Edition - Page 8 preview image

Loading page ...

Methods for Describing Sets of Data72.8a.From the pie chart, 50.4% or 0.504 of adults living in the U.S. use the internet and payto download music. From the data, 506 out of 1,003 adults or 506/1,003 = 0.504 ofadults in the U.S. use the internet and pay to download music. These two results agree.b.Using MINITAB, a pie chart of the data is:33.0%No Pay67.0%PayCategoryPayNo PayPie Chart of Download-Music2.10a.Data were collected on 3 questions. For questions 1 and 2, the responses were either‘yes’ or ‘no’. Since these are not numbers, the data are qualitative. For question 3, theresponses include ‘character counts’, ‘roots of empathy’, ‘teacher designed’, other’, and‘none’. Since these responses are not numbers, the data are qualitative.b.Using MINITAB, bar charts for the 3 questions are:NoYes6050403020100Classroom PetsCountChart of Classroom Pets

Solution Manual for Statistics, Updated Edition, 13th Edition - Page 9 preview image

Loading page ...

8Chapter 2c.Many different things can be written. Possible answers might be: Most of the classroomteachers surveyed(61 / 750.813)keep classroom pets. A little less than half of thesurveyed classroom teachers(35 / 750.467)allow visits by pets.2.12Using MINITAB, the pie chart is:NoYes403020100Pet VisitsCountChart of Pet VisitsNoneOtherTeacher designedRoots of EmpathyCharacter Counts302520151050EducationCountChart of EducationUrbanSuburbanRuralCategoryRural5.7%Suburban32.8%Urban61.5%Pie Chart of Loc

Solution Manual for Statistics, Updated Edition, 13th Edition - Page 10 preview image

Loading page ...

Methods for Describing Sets of Data92.14a.The two qualitative variables graphed in the bar charts are the occupational titles of clanindividuals in the continued line and the occupational titles of clan individuals in thedropout line.b.In the Continued Line, about 63% were in either the high or the middle grade. Onlyabout 20% were in the nonofficial category. In the Dropout Line, only about 22% werein either the high or middle grade while about 64% were in the nonofficial category.The percentages in the low grade and provincial official categories were about the samefor the two lines.2.16Using MINITAB, the Pareto chart is:From the graph, it appears that tracks #5 and #8 were over-utilized and track #1 is under-utilized.2.18a.Using MINITAB, the Pareto chart of the total annual shootings involving the Bostonstreet gang is:#1#9#4#3#2#11#10#7#6#8#5.14.12.10.08.06.04.020TrackRelative frequencyProportion within all data.Chart of Allocation20102008200920072006.5.4.3.2.10YearProportion of Total ShootingsChart of Total ShootingsProportion within all data.

Solution Manual for Statistics, Updated Edition, 13th Edition - Page 11 preview image

Loading page ...

10Chapter 2b.Using MINITAB, the Pareto chart of the annual shootings of the Boston gang membersis:c.Because the proportion of shootings per year dropped drastically after 2007 for both thetotal annual shootings and annual shootings of the Boston street gang members, itappears that Operation Ceasefire was effective.2.20Using MINITAB, the side-by-side bar graphs showing the distribution of dives for the threematch situations are:From the graphs, it appears that when a team is tied or ahead, there is no difference in theproportion of times the goal-keeper dives right or left. However, if the team is behind, thegoal-keeper tends to dive right much more frequently than left.20102008200920072006.5.4.3.2.10YearProportion of Gang MembersChart of Gang Member ShootingsProportion within all data.RightMiddleLeft.8.6.4.20RightMiddleLeft.8.6.4.20Team behindDiveProportionTiedTeam aheadChart of Team behind, Tied, Team aheadProportion within all data.

Solution Manual for Statistics, Updated Edition, 13th Edition - Page 12 preview image

Loading page ...

Methods for Describing Sets of Data112.22Using MINITAB, a bar graph of the data is:The researcher concluded that “there is a large amount of variation within the museumcommunity with regards to . . . performance measurement and evaluation”.From the data,there are only 5 different performance measures. I would not say that this is a large amount.Within these 5 categories, the number of times each is used does not vary that much. I woulddisagree with the researcher. There is not much variation.2.24Using MINITAB a bar chart for the Extinct status versus flight capability is:It appears that extinct status is related to flight capability. For birds that do have flightcapability, most of them are present. For those birds that do not have flight capability, mostare extinct.MembersFunds raisedBig showsPaying visitorsTotal Visitors9876543210MeasureFreqChart of MeasureExtinctFlightYesNoAbsentYesNoYesNoYesNo80706050403020100CountChart of Extinct, Flight

Solution Manual for Statistics, Updated Edition, 13th Edition - Page 13 preview image

Loading page ...

12Chapter 2The bar chart for Extinct status versus Nest Density is:It appears that extinct status is not related to nest density. The proportion of birds present,absent, and extinct appears to be very similar for nest density high and nest density low.The bar chart for Extinct status versus Habitat is:It appears that the extinct status is related to habitat. For those in aerial terrestrial (TA), mostspecies are present. For those in ground terrestrial (TG), most species are extinct. For thosein aquatic, most species are present.2.26The difference between a bar chart and a histogram is that a bar chart is used for qualitativedata and a histogram is used for quantitative data. For a bar chart, the categories of thequalitative variable usually appear on the horizontal axis. The frequency or relativefrequency for each category usually appears on the vertical axis. For a histogram, values ofthe quantitative variable usually appear on the horizontal axis and either frequency or relativefrequency usually appears on the vertical axis. The quantitative data are grouped intointervals which appear on the horizontal axis. The number of observations appearing in eachinterval is then graphed. Bar charts usually leave spaces between the bars while histogramsdo not.2.28In a histogram, a class interval is a range of numbers above which the frequency of themeasurements or relative frequency of the measurements is plotted.ExtinctNest DensityYesNoAbsentLHLHLH6050403020100CountChart of Extinct, Nest DensityExtinctHabitatYesNoAbsentTGTAATGTAATGTAA403020100CountChart of Extinct, Habitat

Solution Manual for Statistics, Updated Edition, 13th Edition - Page 14 preview image

Loading page ...

Methods for Describing Sets of Data132.30a.This is a frequency histogram because the number of observations is displayed ratherthan the relative frequencies.b.There are 14 class intervals used in this histogram.c.The total number of measurements in the data set is 49.2.32Using MINITAB, the relative frequency histogram is:Class IntervalRelative frequency16.514.512.510.58.56.54.52.50.5.25.20.15.10.0502.34a.Using MINITAB, the relative frequency histogram is:b.From the graph, the proportion of subjects with RDER values between 75 and 105 isabout 0.18. The exact proportion is13 / 710.183.b.From the graph, the proportion of subjects with RDER values below 15 is about0.010.080.09. The exact proportion is16 / 710.099.2.36a.Because the label on the vertical axis is ‘Percent’ , this is a relative frequency histogram.255225195165135105754515-15-450.250.200.150.100.050RDER ValueRelative FrequencyHistogram of RDER

Solution Manual for Statistics, Updated Edition, 13th Edition - Page 15 preview image

Loading page ...

14Chapter 2b.From the graph, the percentage of the 992 senior managers who reported a high level ofsupport for corporate sustainability is about3.82.42.11.21.20.50.70.20.100.112.3%.2.38Using MINITAB, the stem-and-leaf display is:Stem-and-Leaf Display: DepthStem-and-leafofDepthN= 18LeafUnit=0.1021329414008157789(3)161257170851811319347The data in the stem-and-leaf display are displayed to 1 decimal place while the actual data isdisplayed to 2 decimal places.To 1 decimal place, there are 3 numbers that appear twice –14.0, 15.7, and 18.1. However, to 2 decimal places, none of these numbers are the same.Thus, no molar depth occurs more frequently in the data.2.40a.Using MINITAB, the dot plot of the honey dosage data is:b.Both 10 and 12 occurred 6 times in the honey dosage group.c.From the graph in part c, 8 of the top 11 scores (72.7%) are from the honey dosagegroup. Of the top 30 scores, 18 (60%) are from the honey dosage group. This supportsthe conclusions of the researchers that honey may be a preferable treatment for thecough and sleep difficulty associated with childhood upper respiratory tract infection.16141210864Improvement ScoreDotplot of Honey Dosage Group

Solution Manual for Statistics, Updated Edition, 13th Edition - Page 16 preview image

Loading page ...

Methods for Describing Sets of Data152.42a.Using MINITAB, the stem-and-leaf display is:Stem-and-Leaf Display: SpiderStem-and-leafofSpiderN= 10LeafUnit=101003033(3)04554067209111b.The spiders with a contrast value of 70 or higher are in bold type in the stem-and-leafdisplay in parta. There are 3 spiders in this group.c.The sample proportion of spiders that a bird could detect is3 / 100.3. Thus, we couldinfer that a bird could detect a crab-spider sitting on the yellow central part of a daisyabout 30% of the time.2.44a.A stem-and-leaf display of the data using MINITAB is:Stem-and-Leaf Display: FNEStem-and-leafofFNEN= 25LeafUnit=1.0206730861001101333312145(2)16611189997200113232245b.The numbers in bold in the stem-and-leaf display represent the bulimic students. Thosenumbers tend to be the larger numbers. The larger numbers indicate a greater fear ofnegative evaluation. Thus, the bulimic students tend to have a greater fear of negativeevaluation.c.A measure of reliability indicates how certain one is that the conclusion drawn iscorrect. Without a measure of reliability, anyone could just guess at a conclusion.

Preview Mode

This document has 555 pages. Sign in to access the full document!

Report

Study Now!

Document Details

Related Documents

Statistics, 12th Edition Test Bank

Test Bank for Statistics , 8th Edition

Statistics - Univariate Inferential Tests

Statistics - Sampling

Statistics - Probability

Statistics - Principles of Testing

Statistics - Numerical Measures

Statistics - Introduction to Statistics

Statistics - Graphic Displays

Statistics - Cummulative Reviews

Company

Explore

Study Tools