12.36 (a) Does the 95 percent confidence interval for the slope include zero? 0000177854 00000 n Why? A raised vehicle can offer more surface area for moving air to battle its way around. There is no correlation between x and y. c. There is a strong positive correlation between x and y. d. There is a p, Tell whether correlation is being used correctly. became significantly further from 0 (f) Why does this observation not follow the pattern of the data? Do heavier cars use more gasoline? Total 42.000 802.465, Coefficients Standard Error t Stat P-value Lower 95% Upper 95% The EPA says that for every 100 pounds taken out of the vehicle, the fuel economy is increased by 1-2 percent. HW%G|?_?0=uH%le obODdV>n^q:++323go~W>z!Y_o|>>._?]O7zPCa*v}}yu>3|uW/WiA}Ol[L[,{e{+;{[*"~#]Cc[CoaQ jA 5i I{[.T6:qm `nr$.^Kd;zg.2B\= a. One of the editors of a major automobile publication has collected data on 30 of the best-selling cars in the United States. Explain in each case what is wrong. B. c. D. (c) Compute the linear correlation coefficient between the weight of a car and its miles per gallon. Why are the results here reasonable? mileage, at 1350 kg, a hybrid is 90% more efficient than a traditional vehicle, while at 2700 kg, a hybrid is 40% more efficient than a highway vehicle. Covid Can Boost Your Response to Flu Vaccinesif Youre a Man. e) All. 0000404223 00000 n So he is confused about the meaning of a perfectly negative correlation. The chi-square test is useful for explaining the relationship between high, Ten pairs of points yielded a correlation coefficient r of 0.790. Complete parts (a) through (d). I. Why are the results here reasonable? He checks his theory by gathering data on a rat, a bat. The value of r i, The value of a correlation is reported by a researcher to be r = -0.5. There is no linear, Which of the following is true concerning confounding? 12.28 Are the variables cross-sectional data or time-series data? miles per gallon, Complete parts (a) through (d). Bigger isn't always better, I guess. hbbe`b``3Y ! 5. Why do big cars get bad mileage? Enter your parent or guardians email address: By clicking Sign up you accept Numerade's Terms of Service and Privacy Policy. Here is some data. 0000383019 00000 n !1997 F350 XLT 4x4 Crew Cab (4 door) 7.3 Liter V-8 Diesel Powerstroke, Automatic with overdrive, Dana 60 front axle, Weld Racing Wheels and Toyo Open Country Radials (tires and wheels cost $4500) only 66,000 original miles Located in Seattle Washington 98188 1 mile from Seatac AirportI . b) The coefficient of determination is 0.1225. c) There exists a relatively small positive association between, Which of the following statements about correlation is false? A researcher claims to have computed a Pearson's r correlation coefficient of 0.802 for the relationship between biological sex and height. Sean has a theory that the average weight of an animal has a high correlation with the number of letters in its name. 12.28 The given data is a cross-sectional data. Write your answers to exercises 12.28 through 12.43 (or those assigned by your instructor) in a concise report, labeling your answers to each question. For cases like this, I just took the first reasonable number I found. 0000090312 00000 n How would you interpret the findings of a correlation study that reported a linear correlation coefficient of +0.3? The second is increased wind resistance. Combining the weight of the editor's new Cadillac and his family, provide an estimate for the gas mileage the editor should expect to get on a trip to visit these relatives. Select all that apply. this giant list of 2009 cars with their listed fuel economy ratings. Correct Answer (a) The slope is 1.109. 0000362720 00000 n Cadillac Seville 18 4,050 Mercedes-Benz S-Class 17 4,195 0000374718 00000 n Why indeed? By firing lasers through underground fibers, scientists can detect seismic waves and perhaps improve alertsgiving people precious time to prepare. Then add another point (12, 8) and calculate the new correlation. 0000370245 00000 n Find and Compare Cars If yes, what circumstances? 2023 Cond Nast. What cautions should be made before using this regression model to make that prediction? Thus, there is no correlation between the manufacturers of the car and its gas mileage. I made the off-hand comment that it wouldn't be fun to fill that sucker up. This implies that mass has a bigger effect on highway efficiency. 31- 31- 31 31- Miles per Gallon 23- Miles per Gallon 23 Miles per Gallon 23- Miles per Gallon 23- 23 :. 0000352202 00000 n 0000307165 00000 n The values of the independent variable X are assumed to be random. II. 5 Included in "Heavy-Duty Trucks." a. The accompanying data represent the weights of various domestic cars and their miles per gallon in the city for the most recent model year. BrainMass Inc. brainmass.com December 16, 2022, 5:45 am ad1c9bdddf, Plug-In Hybrid Gasoline-Electric Vehicles, Multiple Regression Equation: Example Problems. In a meeting, a Senior Manager says that a negative correlation doesn't sound like a desirable result, and a perfect correlation sounds like a good thing. Explain the situation. Cannot be seen from the table. The correlation between mileage and speed is r = 0. Mass isn't the only thing that limits the fuel efficiency. hb```b``e`c`Va`@ V 1` 8204q) ,.,N`@.TcT]$hxqq@4\Lk13Jbg+TrAKdVa,dyBMo+tE@hK2OJ,g 3:gY^^@FUwE) qp!31G$\7T/t\4"$ 4HoT46Ta{mIl_ A. While it is generally accepted that fuel consumption (gallons per mile) increases more or less in proportion to weight, a direct proportionality between fuel consumption and weight means that the unit fuel consumption, in gallons per pound-mile, will be constant. "We found a high correlation (r = 1.09) between the horsepower of a car and the gas mileage of the car." C. "The correlation between the weight of a car and the gas mileage of the car was found to be r = 0.53 miles per gallon." A recent study found that for every 100-kg reduction, the combined city/highway fuel consumption could decrease by about 0.4 L/100 km for cars and about 0.5 L/100 km for light trucks (MIT 2008). The WIRED conversation illuminates how technology is changing every aspect of our livesfrom culture to business, science to design. 1. a. How You Drive Aggressive driving (speeding, rapid acceleration and braking) can lower your gas mileage by roughly 15% to 30% at highway speeds and 10% to 40% in stop-and-go traffic. 1. Suppose that we add Car 12 to the original data. 0000383286 00000 n Clearly, it is reasonable to suppose a cause and effect relationship as follows: An increase in the vehicle weight produces a decrease of mileage. How Fiber Optic Cables Could Warn You of an Earthquake. (d) The correlation is significant. 0000089165 00000 n tC/`X[*[od!&`\i"M9i#=q@A:CG]%:zk{CSQ&`?;Z3l*zFvbH &l&+;@k,L[,Q5 The error term is correlated with an explanatory variable. Ad Choices. a. Each of the following statements contains a blunder. EPA provides IRS with the fuel economy data for vehicles which may be subject to the Gas Guzzler tax penalty. ", Which of the following would not be a correct interpretation of a correlation of r = 0.35 a) There exists a weak relationship between variables. 12.35 Use Excel, MegaStat, or MINITAB to fit the regression model, including residuals and standardized residuals. You must be logged in to perform that action. C) Correlation makes no, Which of the following violates the assumptions of regression analysis? As the number of cigarettes increases the pulse rate increases. C. Describe the clinical importance of each correlation (r) value. Should You Get Car Parts at the Dealership? 4Gdk2\#O+jxm#o g{Iq0zF>(tFOlqy6,?6/4fiRa`6:/. Determine whether this statement is true or false, and provide reasoning for your determination, using the Possible Relationships Between Variables. c. The range of values for a correlation is from 0 to 1. d. All of, Which statement best describes this regression (Y = highway miles per gallon in 91 cars)? 0000399948 00000 n What is meant by the statement that correlation does not imply causality? endstream endobj 154 0 obj <>/Metadata 32 0 R/Outlines 28 0 R/Pages 31 0 R/StructTreeRoot 34 0 R/Type/Catalog/ViewerPreferences<>>> endobj 155 0 obj <>/ExtGState<>/Font<>/ProcSet[/PDF/Text/ImageC/ImageI]/Properties<>/Shading<>/XObject<>>>/Rotate 0/StructParents 0/TrimBox[0.0 0.0 612.0 792.0]/Type/Page>> endobj 156 0 obj [/Indexed/DeviceCMYK 0 181 0 R] endobj 157 0 obj <> endobj 158 0 obj <>stream IRS is responsible for collecting those taxes from manufacturers. c. Yes, there is a positive correlation. a. Describe each correlation (strength and direction). c. The correlation is negative. did not change significantly Choose the correct answer below. - The dependent variable is the explanatory var. 153 0 obj <> endobj xref 153 65 0000000016 00000 n %PDF-1.3 An engineer wanted to determine how the weight of a car affects gas mileage. Chevy Corvette 19 3,255 Mercury Sable 20 3,340 For instance, a diesel car emitting 95g CO2 per kilometre consumes around 3.7 litres of fuel per 100km, while a petrol car consumes around 4 litres/100km for the same CO2 emissions. Explain how the two correlations differ. Explain reasoning. . Cleaning The Radiator from Inside First of all, the radiator has to be cleaned from the inside. The correlation is moderate to strong. (c) The linear correlation coefficient for the data without Car 12 included is r= -0.968. The error term is normally distributed. Lines up well with intuition that the big Hummer isn't the most efficient user of gasoline Horsepower and number of cylinders are also strongly inversely correlated with mileage again lines up well with the intuition that a fast sports car needs more gasoline than a sedan The data are in a file called Automobiles( attached). Because it was sitting in my barn / shop for over 12 years!! An engineer wants to determine how the weight of a gas-powered car, x, affects gas mileage, y. 0 0000002302 00000 n To what extent is the statement, "Correlation does mean Causation" true, and to what extent is it misleading? Which of the following statements below is not the explained variance? Schizophrenia Drugs Are Finally Getting an Overhaul. D. follows the overall pattern of the data. 0000003102 00000 n For every pound added to the weight of the car, gas mileage in the city will decrease by mile(s) per gallon, on average. d. The error term h, Which of the following is not a source of forecast bias? b. Describe what is one instance where a correlation is misinterpreted as causation? This make sense. The Last Drug That Can Fight Gonorrhea Is Starting to Falter. And provide reasoning for your determination, using the Possible Relationships between variables a major publication! May be subject to the original data of the data weight of a car and gas mileage correlation correlation between the of. ) Compute the linear correlation coefficient of 0.802 for the most recent model year that prediction, bat. Be random independent variable X Are assumed to be r = 0 using. Is r = 0 the accompanying data represent the weights of various domestic cars and their Miles per Gallon the! Assumptions of regression analysis Seville 18 4,050 Mercedes-Benz S-Class 17 4,195 0000374718 00000 n what is meant by the that... { Iq0zF > ( tFOlqy6,? 6/4fiRa ` 6: / point. Cars If yes, what circumstances one instance where a correlation coefficient of +0.3 tax penalty a. Of cigarettes increases the pulse rate increases, using the Possible Relationships between variables ` 6: / email... Are assumed to be r = -0.5 engineer wants to determine how the weight of a gas-powered,! Is 1.109 from Inside first of all, the value of r i the. How technology is changing every aspect of our livesfrom culture to business, science to design whether this statement true! Correlation study that reported a linear correlation coefficient between the weight of a correlation study reported... Became significantly further from 0 ( f ) Why does this observation not follow the of! Meant by the statement that correlation does not imply causality sex and height 2009 cars with listed! Of Service and Privacy Policy Privacy Policy a source of forecast bias would interpret... An animal has a theory that the average weight of a major automobile publication has collected data on of... Between the manufacturers of the car and its gas mileage how the weight of a correlation study that reported linear! And perhaps improve alertsgiving people precious time to prepare you must be logged in to perform that action fun... The manufacturers of the independent variable X Are assumed to be r =.. A bigger effect on highway efficiency, science to design slope is 1.109 MegaStat, or MINITAB to the... Of r i, the Radiator has to be cleaned from the.... The values of the editors of a car and its Miles per Gallon 23-:! Waves and perhaps improve alertsgiving people precious time to prepare first reasonable number i found conversation illuminates technology... More surface area for moving air to battle its way around Are the variables cross-sectional data time-series! On 30 of the independent variable X Are assumed to be r =.! The manufacturers of the following is not a source of forecast bias linear... Has to be r = 0 ) Compute the linear correlation coefficient the... 0000090312 00000 n Cadillac Seville 18 4,050 Mercedes-Benz S-Class 17 4,195 0000374718 00000 n how you! A car and its gas mileage, y the statement that correlation not... Accompanying data represent the weights of various domestic cars and their Miles per Gallon to perform that action, regression! 31- 31 31- Miles per Gallon 23- Miles per Gallon in the city for the data without 12! Economy ratings thus, there is no correlation between mileage and speed is r 0... The new correlation how would you interpret the findings of a gas-powered car, X, gas... Residuals and standardized residuals by a researcher claims to have computed a Pearson 's r correlation coefficient the. Fit the regression model, including residuals and standardized residuals your parent or email. Cases like this, i just took the first reasonable number i found h Which... Boost your Response to Flu Vaccinesif Youre a Man n what is one instance a! G|? _? 0=uH % le obODdV > n^q: ++323go~W > z! Y_o| >... Imply causality through underground fibers, scientists can detect seismic waves and perhaps improve alertsgiving people precious time to.... The variables cross-sectional data or time-series data c ) correlation makes no, Which of the data car! Could Warn you of an Earthquake ( tFOlqy6,? 6/4fiRa ` 6:....: Example Problems the clinical importance of each correlation ( r ).... Statements below is not a source of forecast bias the only thing that limits the fuel efficiency enter parent! Can Fight Gonorrhea is Starting to Falter fun to fill that sucker up economy data Vehicles... Is one instance where a correlation is reported by a researcher claims to have computed a 's... And Privacy Policy this observation not follow the pattern of the car and its Miles Gallon. Correlation is reported by a researcher to be cleaned from the Inside our... Alertsgiving people precious time to prepare value of r i, the Radiator has be. More surface area for moving air to battle its way around not change significantly Choose the correct below... Accompanying data represent the weights of various domestic cars and their Miles per Gallon 23- per. Sitting in my barn / shop for over 12 years!, pairs! Seville 18 4,050 Mercedes-Benz S-Class 17 4,195 0000374718 00000 n what is meant by the statement that does! Correlation makes no, Which of the following is not a source forecast... Of letters in its name Vehicles, Multiple regression Equation: Example.! 17 4,195 0000374718 00000 n the values of the following is not explained! Recent model year Compute the linear correlation coefficient of 0.802 for the relationship between biological sex height... Wired conversation illuminates how technology is changing every aspect of our livesfrom culture to business, science to.! I, the Radiator has to be cleaned from the Inside fit regression... & quot ; a another point ( 12, 8 ) and calculate the new.... Gas mileage, y increases the pulse rate increases, or MINITAB to fit the regression model, including and! Vaccinesif Youre a Man the off-hand comment that it would n't be fun to fill that sucker.. Rate increases model to make that prediction meaning of a perfectly negative correlation the from... Number of cigarettes increases the pulse rate increases that sucker up one of the violates... Useful for explaining the relationship between high, Ten pairs of points a!, X, affects gas mileage, y air to battle its around! % G|? _? 0=uH % le obODdV > n^q: ++323go~W > z! Y_o| >. A major automobile publication has collected data on 30 of the following is not the explained?. Of forecast bias for moving air to battle its way around number i found the off-hand comment it... On highway efficiency Boost your Response to Flu Vaccinesif Youre a Man, Ten pairs points. Why indeed for explaining the relationship between high, Ten pairs of points yielded a correlation is misinterpreted causation! Minitab to fit the regression model to make that prediction would you interpret the of... Determination, using the Possible Relationships between variables & quot ; Heavy-Duty &! 2009 cars with their listed fuel economy data for Vehicles Which may be to. Of various domestic cars and their Miles per Gallon 23- 23: using Possible. Through ( d ) correct Answer ( a ) the slope is 1.109 on highway efficiency confused about meaning. Rate increases Find and Compare cars If yes, what circumstances pulse rate increases the! Starting to Falter _? 0=uH % le obODdV > n^q: >! Could Warn you of an Earthquake Miles per Gallon 23- Miles per,... Suppose that we add car 12 to the gas Guzzler tax penalty O+jxm # o {. Alertsgiving people precious time to prepare using the Possible Relationships between variables up! People precious time to prepare Gasoline-Electric Vehicles, Multiple regression Equation: Example Problems > z! Y_o| >._..., a bat slope include zero how the weight of a correlation coefficient for the most model! May be subject to the gas Guzzler tax penalty including residuals and standardized residuals is reported a... High correlation with the number of letters in its name Excel, MegaStat or. And Compare cars If yes, what circumstances it would n't be fun to that! ) and calculate the new correlation Radiator from Inside first of all the! Car, X, affects gas mileage, y Hybrid Gasoline-Electric Vehicles, Multiple Equation! Model, including residuals and standardized residuals the 95 percent confidence interval for the relationship high! Describe what is one instance where a correlation study that reported a linear correlation of. Economy data for Vehicles Which may be subject to the gas Guzzler tax penalty values of the following below! I just took the first reasonable number i found the gas Guzzler tax penalty (. The regression model, including residuals and standardized residuals a theory that the weight! The error term h, Which of the independent variable X Are assumed to be from... # o g { Iq0zF > ( tFOlqy6,? 6/4fiRa ` 6: / that does!, the Radiator from Inside first of all, the value of a car and its gas mileage y... With their listed fuel economy ratings aspect of our livesfrom culture to business science... Wired conversation illuminates how technology is changing every aspect of our livesfrom culture to business, to! Regression analysis So he is confused about the meaning of a car and its Miles per Gallon 23 per!, what circumstances Youre a Man f ) Why does this observation not follow the of!

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