Introduction to the practice of statistics 9th edition by moore mccabe craig test bank

Introduction to the Practice of Statistics 9th edition by David S Moore, George P McCabe, Bruce A Craig Test Bank Link full download: https://findtestbanks.com/download/introduction-to-the-practice-ofstatistics-9th-edition-by-moore-mccabe-craig-test-bank/ Fill in the blank When creating a scatterplot, one should use the _ axis for the explanatory variable if a regression line is to be fit to the data Fill in the blank A study is conducted to determine if one can predict the yield of a crop based on the amount of yearly rainfall The variable _ is the response variable in this study Fill in the blank A researcher is interested in determining if one could predict the score on a statistics exam from the amount of time spent studying for the exam The variable _ is the explanatory variable in this study Fill in the blank The Environmental Protection Agency records data on the fuel economy of many different makes of cars They are interested in determining if one could predict the mileage of the car (in miles per gallon) from the weight of the car (in lbs.) The variable _ is the response variable in this study Fill in the blank The owner of a winery collects data on competing wineries every year He would like to predict the gross sales (in number of cases) from the size of the wineries (in acres) The variable _ is the explanatory variable in this study Fill in the blank A scatterplot is a graphical tool for displaying the relationship between two variables measured on the same individuals Page A researcher measured the height (in feet) and volume of usable lumber (in cubic feet) of 32 cherry trees The goal is to determine if the volume of usable lumber can be estimated from the height of a tree The results are plotted below: Fill in the blank The variable _ is the response variable in this study Page A researcher measured the height (in feet) and volume of usable lumber (in cubic feet) of 32 cherry trees The goal is to determine if the volume of usable lumber can be estimated from the height of a tree The results are plotted below: Select all descriptions that apply to the scatterplot A) There is a positive association between height and volume B) There is a negative association between height and volume C) There is an outlier in the plot D) The plot is skewed to the left E) Both A and C Page The graph below is a plot of the fuel efficiency (in miles per gallon, or mpg) of various cars versus the weight of these cars (in thousands of pounds) The points denoted by the plotting symbol × correspond to pick-up trucks and SUVs The points denoted by the plotting symbol correspond to automobiles (sedans and station wagons) What can we conclude from this plot? A) There is little difference between trucks and automobiles B) Trucks tend to be higher in weight than automobiles C) Trucks tend to get poorer gas mileage than automobiles D) The plot is invalid A scatterplot is used to represent quantitative variables, and the vehicle type is a qualitative variable E) Both B and C Page 10 Volunteers for a research study were divided into three groups Group listened to Western religious music, Group listened to Western rock music, and Group listened to Chinese religious music The blood pressure of each volunteer was measured before and after listening to the music, and the change in blood pressure (blood pressure before listening minus blood pressure after listening) was recorded What could we to explore the relationship between type of music and change in blood pressure? A) See if blood pressure decreases as type of music increases by examining a scatterplot B) Make a histogram of the change in blood pressure for all of the volunteers C) Make side-by-side boxplots of the change in blood pressure, with a separate boxplot for each group D) All of the above Page 11 Volunteers for a research study were divided into three groups Group listened to Western religious music, Group listened to Western rock music, and Group listened to Chinese religious music The blood pressure of each volunteer was measured before and after listening to the music, and the change in blood pressure (blood pressure before listening minus blood pressure after listening) was recorded A scatterplot of change in blood pressure (mmHg) versus the type of music listened to is given below: What we know about the correlation between change in blood pressure and type of music? A) It is negative B) It is positive C) It is first negative then positive D) None of the above 12 To examine the relationship between two variables, the variables must be measured from the same _ A) cases B) labels C) units D) values Page 13 Variables measured on the same cases are _ if knowing the values of one of the variables gives you information about the values of another variable that was not known beforehand A) transformed B) categorical C) associated D) quantitative 14 A variable that explains or causes change to another variable is called a(n) _ variable A) independent B) dependent C) response 15 Two variables are if knowing the values of one of the variables gives one information about the other variable A) associated B) lurking C) confounded 16 We are interested in determining if students who graduate from larger universities receive greater starting salaries than students who graduate from smaller universities We collected data from 50 small universities and 50 large universities to examine this relationship This is an example of A) exploratory data analysis B) benchmarking C) data mining 17 True or False A categorical variable can be added to a scatterplot A) True B) False Page 18 The scatterplot below displays data collected from 20 adults on their age and overall GPA at graduation True or False The scatterplot shows a strong relationship A) True B) False Page 19 The scatterplot below displays data collected from 20 adults on their age and overall GPA at graduation True or False If you switched the variables on the x and y axis, the relationship between the two variables would appear much stronger A) True B) False Page 202 Let x = the amount of money spent per pupil in high school Let y = the mean Verbal SAT score for students taking the SAT Recent data show that states having an aboveaverage value for the variable x tend to have below-average values for the variable y In other words, there is a negative association between x and y This is particularly true in states having a large percentage of all high school students taking the SAT These states also tend to have larger populations What is the most plausible explanation for this association? A) Causation: x causes y Overspending generally leads to extra, unnecessary programs, diverting attention from basic subjects Inadequate training in these basic subjects generally leads to lower SAT scores B) Causation: y causes x Low SAT scores create concerns about the quality of education This inevitably leads to additional spending to help solve the problem C) Common response: Changes in x and y are due to a common response to other variables If a higher percentage of students take the SAT, the average score will be lower Also, states with larger populations have large urban areas where the cost of living is higher and more money is needed for expenses D) Accidental: The association between x and y is purely coincidental It is implausible to believe the observed association could be anything other than accidental 203 As Swiss cheese matures, a variety of chemical processes take place The taste of matured cheese is related to the concentration of several chemicals in the final product Let x = the lactic acid concentration of the cheese and y = the taste score of the cheese, which was obtained by combining the scores from several tasters According to a study of cheese in a certain region of Switzerland, those samples of cheese having an aboveaverage value for the variable x tended to have an above-average value for y In other words, there was a positive association between x and y What is the most plausible explanation for this association? A) Causation: x causes y Thus, increasing the lactic acid concentration in cheese will generally help improve the taste B) Common response: Changes in x and y are due to a common response to other variables For example, cheese samples that have matured longer will have higher lactic acid concentrations, and more mature cheese tends to receive higher taste scores C) Common response: Changes in x and y are due to a common response to other variables For example, cheese with a higher concentration of hydrogen sulfide (another chemical present in cheese) will have higher lactic acid concentrations and will receive higher taste scores D) Accidental: The association between x and y is purely coincidental It is implausible to believe the observed association could be anything other than accidental Page 103 204 An article in the student newspaper of a large university had the headline “A's swapped for evaluations?” The article included the following paragraph: According to a new study, teachers may be more inclined to give higher grades to students, hoping to gain favor with the university administrators who grant tenure The study examined the average grade and teaching evaluation in a large number of courses in order to investigate the effects of grade inflation on evaluations “I am concerned with student evaluations because instruction has become a popularity contest for some teachers,” said Professor Smith, who recently completed the study Results showed higher grades directly corresponded to a more positive evaluation Based on the statement underlined above, what did the study find out about the relationship between course grade and teaching evaluation? A) Course grade is positively associated with teaching evaluation B) There must be a common response that course grade and teaching evaluation both respond to Higher grades are usually obtained by the more serious students These students are also more apt to fill out the course evaluation more seriously and positively C) The association between course grade and teaching evaluation is purely coincidental D) There is a cause-and-effect relationship between course grade and teaching evaluation 205 An article in the student newspaper of a large university had the headline “A's swapped for evaluations?” The article included the following paragraph: According to a new study, teachers may be more inclined to give higher grades to students, hoping to gain favor with the university administrators who grant tenure The study examined the average grade and teaching evaluation in a large number of courses in order to investigate the effects of grade inflation on evaluations “I am concerned with student evaluations because instruction has become a popularity contest for some teachers,” said Professor Smith, who recently completed the study Results showed higher grades directly corresponded to a more positive evaluation Which of the following would be a valid conclusion to draw from the study? A) A teacher can improve their teaching evaluations by giving good grades B) A good teacher, as measured by teaching evaluations, helps students to learn better, resulting in higher grades C) Teachers of courses in which the mean grade is above average apparently tend to have above-average teaching evaluations D) All of the above Page 104 206 Which set of two variables is most likely to have a cause-and-effect relationship? A) The height of a person and the weight of a person B) The weight of a box and the postage rate we have to pay to ship the box to California C) The make of a car and the mileage of the car D) The age of a teacher and the income of the teacher 207 A researcher computed the average Math SAT score of all high school seniors who took the SAT exam for each of the 50 states The researcher also computed the average salary of high school teachers in each of these states and plotted these average salaries against the average Math SAT scores for each state The plot showed a distinct negative association between average Math SAT scores and average teacher salaries The researcher can legitimately conclude which of the following? A) Increasing the average salary of teachers will cause the average of Math SAT scores to decrease, but it is not correct to conclude that increasing the salaries of individual teachers causes the Math SAT scores of individual students to increase B) States that pay teachers highly tend to a poor job of teaching mathematics C) States whose students tend to perform poorly in mathematics probably have a higher proportion of problem students and thus need to pay teachers higher salaries in order to attract them to teach in those states D) The data used by the researcher not provide evidence that increasing the salary of teachers will cause the performance of students on the Math SAT to get worse 208 A researcher is conducting a study on contact lenses She finds that in a sample of contact lens-wearing adults, those who wear their contact lenses for longer periods of time have more irritation in their eyes Those who wear their contact lenses for only a few hours a day have less irritation However, those who wear their contacts for longer times also tend to spend long hours at the office As explanations for having more irritation in the eyes, the variables “length of time contacts are worn each day” and “length of time spent at the office per day” are variables A) response B) independent C) confounding D) placebo Page 105 209 A researcher notices that in a sample of adults, those who take larger amounts of vitamin C have fewer illnesses However, those who take larger amounts of vitamin C also tend to exercise more As explanations for having fewer illnesses, the variables “amount of vitamin C taken” and “amount of exercise” are variables A) skewed B) confounding C) response D) symmetric 210 Which of the following statements about causation and association is/are FALSE? A) Some observed associations between two variables are due to a lurking variable rather than a cause-and-effect relationship between the two variables B) Some possible explanations of an observed association are causation, common response, or confounding C) When many variables interact with each other, confounding of several variables often prevents a conclusion about causation to be reached D) To establish that association is due to causation, it is best to conduct an experiment that makes changes to the explanatory variable while controlling other influences on the response variable E) When strong association between two variables is present, this is often sufficient evidence to establish that the association is because of a causal link 211 True or False Two variables are confounded when their effects on a response variable can be distinguished from each other A) True B) False 212 Interest rates for home mortgages have, in general, declined during recent months With the apparent favorable influence for new-home building, there seems to be a clear relationship between x = the prevailing mortgage interest rates and y = the number of new houses being built per month in a Midwestern city over a period of 18 months A scatterplot of the data collected shows that the linear model is appropriate The equation of the least-squares regression line is Number of new houses = 672.89 – 30.65 × Interest rate and r = 0.49 Is the association between Interest rate and Number of new houses being built positive or negative? Page 106 213 Interest rates for home mortgages have, in general, declined during recent months With the apparent favorable influence for new-home building, there seems to be a clear relationship between x = the prevailing mortgage interest rates and y = the number of new houses being built per month in a Midwestern city over a period of 18 months A scatterplot of the data collected shows that the linear model is appropriate The equation of the least-squares regression line is Number of new houses = 672.89 – 30.65 × Interest rate and r = 0.49 What is the correlation coefficient between Interest rate and Number of new houses being built? 214 Interest rates for home mortgages have, in general, declined during recent months With the apparent favorable influence for new-home building, there seems to be a clear relationship between x = the prevailing mortgage interest rates and y = the number of new houses being built per month in a Midwestern city over a period of 18 months A scatterplot of the data collected shows that the linear model is appropriate The equation of the least-squares regression line is Number of new houses = 672.89 – 30.65 × Interest rate and r = 0.49 Predict the Number of new houses being built for a month when the Interest rate is 10.2 215 Interest rates for home mortgages have, in general, declined during recent months With the apparent favorable influence for new-home building, there seems to be a clear relationship between x = the prevailing mortgage interest rates and y = the number of new houses being built per month in a Midwestern city over a period of 18 months A scatterplot of the data collected shows that the linear model is appropriate The equation of the least-squares regression line is Number of new houses = 672.89 – 30.65 × Interest rate and r = 0.49 Which of the following descriptions below best represents the value of the slope? A) When no new houses are being built, the interest rate equals 30.65% B) When the number of new houses being built increases by 1, the interest rate is expected to drop by 0.3065 C) When the interest rate increases by 1%, the number of new houses being built is expected to drop by 30.65 D) We cannot interpret the slope because we cannot build a negative number of new houses Page 107 216 Interest rates for home mortgages have, in general, declined during recent months With the apparent favorable influence for new-home building, there seems to be a clear relationship between x = the prevailing mortgage interest rates and y = the number of new houses being built per month in a Midwestern city over a period of 18 months A scatterplot of the data collected shows that the linear model is appropriate The equation of the least-squares regression line is Number of new houses = 672.89 – 30.65 × Interest rate and r = 0.49 What is the most plausible explanation for the association between Interest rate and Number of new houses being built? A) Confounding B) Common response C) Causation D) Accidental 217 A simple random sample of eight drivers was selected All eight drivers are insured with the same insurance company, and all have similar auto insurance policies The following table lists their driving experiences (in years) and monthly auto insurance premiums: Driving experience (years) Monthly auto insurance premium ($) 64 77 Which of the two variables is the explanatory variable? Page 108 12 50 71 15 44 25 16 56 42 60 218 A simple random sample of eight drivers was selected All eight drivers are insured with the same insurance company, and all have similar auto insurance policies The following table lists their driving experiences (in years) and monthly auto insurance premiums: Driving experience (years) Monthly auto insurance premium ($) 64 77 12 50 71 15 44 25 16 56 42 60 The equation of the least-squares regression line is yˆ = 72.7 – 1.3x Sketch the line on the scatterplot below Include the labels for the two axes 219 A simple random sample of eight drivers was selected All eight drivers are insured with the same insurance company, and all have similar auto insurance policies The following table lists their driving experiences (in years) and monthly auto insurance premiums: Driving experience (years) Monthly auto insurance premium ($) 64 77 12 50 71 15 44 25 16 56 42 60 Complete the following sentence that explains what the value of the slope tells us: When driving experience (choose one) increases / decreases by we expect the average monthly auto insurance premium to (choose one) increase / decrease by Page 109 220 A simple random sample of eight drivers was selected All eight drivers are insured with the same insurance company, and all have similar auto insurance policies The following table lists their driving experiences (in years) and monthly auto insurance premiums: Driving experience (years) Monthly auto insurance premium ($) 64 77 12 50 71 15 44 25 16 56 42 60 The correlation coefficient between driving experience and monthly auto insurance premium is r = –0.775 If we switch the roles of explanatory and response variables, what would happen to the correlation coefficient? 221 A simple random sample of eight drivers was selected All eight drivers are insured with the same insurance company, and all have similar auto insurance policies The following table lists their driving experiences (in years) and monthly auto insurance premiums: Driving experience (years) Monthly auto insurance premium ($) 64 77 12 50 71 15 44 25 16 56 42 60 Predict the monthly auto insurance premium for a driver with 10 years of driving experience 222 A plot of the residuals versus the x variable is shown below: Based on the residual plot, does the linear regression seem appropriate? Explain briefly Page 110 223 Do heavier cars use more gasoline? To answer this question, a researcher randomly selected 15 cars He collected data about the weight (in hundreds of pounds) and the mileage (mpg) for each car From a scatterplot made with the data, a linear model seems appropriate Fill in the blank The variable is the response variable in this study 224 Do heavier cars use more gasoline? To answer this question, a researcher randomly selected 15 cars He collected data about the weight (in hundreds of pounds) and the mileage (mpg) for each car From a scatterplot made with the data, a linear model seems appropriate Fill in the blank The variable is the explanatory variable in this study 225 Do heavier cars use more gasoline? To answer this question, a researcher randomly selected 15 cars He collected data about the weight (in hundreds of pounds) and the mileage (mpg) for each car From a scatterplot made with the data, a linear model seems appropriate The equation of the least-squares regression line is yˆ = 40.4 – 0.521x Which of the following descriptions of the value of the slope is the correct description? A) The mileage is expected to decrease by 0.521 when the weight of a car increases by pound B) The mileage is expected to decrease by 0.521 when the weight of a car increases by 100 pounds C) The mileage is expected to decrease by 52.1 when the weight of a car increases by 100 pounds D) We cannot interpret the slope because we cannot have a negative weight of a car 226 Do heavier cars use more gasoline? To answer this question, a researcher randomly selected 15 cars He collected data about the weight (in hundreds of pounds) and the mileage (mpg) for each car From a scatterplot made with the data, a linear model seems appropriate The percentage of variation in mileage that is accounted for by the linear relationship between mileage and weight is approximately 44% What is the value of the correlation coefficient between the weight and the mileage of a car? Page 111 Answer Key 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 horizontal yield of the crop amount of time spent studying for the exam mileage of the car size of the winery quantitative volume of usable lumber E E C D A C A A B A B B A A D A B B D B A B B independent dependent A A E E C C B A A A B A Page 112 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 F E B Malaria = 0.731 minus 0.004 Dewpoint 0.1688 B A A) False, B) False, C) False, D) False C A A B C C A) False, B) False, C) True, D) False A) False, B) False, C) False, D) True A) False, B) False, C) False, D) True A) False, B) False, C) False, D) False B C A C E A C A) –0.7, B) 0.95, C) 0.4, D) –0.9 C A) True, B) False, C) False, D) False A A) False, B) False, C) True, D) False D D C C C C B A B A D C B B E A Page 113 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 A B B A A B A B B B A E A D A B C B B A E 51.69 B C B D C A) False, B) True, C) False, D) True B B A D D C B B E B D D E A) False, B) True, C) False, D) False A Extrapolation is the use of the regression line for prediction outside the range of values observed for the explanatory variable x 135 The fraction of the variance of the response variable that is explained by least-squares Page 114 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 regression on the explanatory variable A B C A B A) False, B) True, C) False, D) False A) True, B) True, C) True A D D B B C A) Can't tell, B) Can't tell, C) Yes, D) Can't tell B X B D C A C C A A C D D B C B C A C B D D C B D C D B D B C Page 115 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 A C D B C D D C B 32/400 = 0.08 12/100 = 0.12 20/100 = 0.20 02 65 20 80 C D D E C C A A C B D C B E B Negative –0.7 360.26 C B Driving experience (in years) Page 116 219 When driving experience increases by year, we expect the average monthly auto insurance premium to decrease by $1.30 220 The correlation coefficient would stay the same 221 $59.70 222 Yes, it seems appropriate because there is no clear pattern present in the graph 223 mileage 224 weight 225 B 226 r = –0.663 Page 117 ... values of the two variables in the scatterplot tend to occur together B) high values of one variable tend to occur with low values of the other variable C) there is a positive association D) there... or mpg) of various cars versus the weight of these cars (in thousands of pounds) The points denoted by the plotting symbol × correspond to pick-up trucks and SUVs The points denoted by the plotting... calculating the correlation, r, it is important to make sure x is the explanatory variable and the y is the response variable C) None of the above 54 Which one of the following statements is TRUE? A) The