Suppose that you are given the following results. a. explanatory variable response variable b) Draw a scatter diagram . The accompanying data represent the weights of various domestic cars and their miles per gallon in the city for the most recent model year. c. In negatively skewed distributions, the mean is usually greater than the m. Compute the correlation for the following data. became significantly further from 0 (f) Why does this observation not follow the pattern of the data? Determine whether the correlation coefficient is an appropriate summary for the scatter-plot and explain your reasoning. b. 0.9184 b. Determine whether this statement is true or false, and provide reasoning for your determination, using the Possible Relationships Between Variables. (c) The correlation is not significant. Fuel efficiency, sometimes referred to as fuel economy, is the relationship . mpg = miles per gallon mpg US = miles per United States gallon mpg Imp = miles per Imperial gallon km/l = kilometers per liter l/100km = liters per 100 kilometers Odometer Readings Calculate gas mileage by odometer readings: enter your starting and ending odometer readings and the amount of fuel used for the trip. Was I just making that stuff up? 0
The amount of CO2 a car emits is directly related to the amount of fuel it consumes. 0000362028 00000 n
c. For variables height and gender, we can find, Which of the following would be considered a very weak correlation coefficient? B. The probability that the null hypothesis is true is less than 1 percent. b. Which statement does not belong?
The following problem uses a regression model to answer several questions associated with auto travel. Ultimately, you can't trace fuel economy simply to the level of horsepower your engine is capable of providing. What does the y-intercept mean? 12.28 The given data is a cross-sectional data. Observation Predicted An analysis for mileage and vehicle weight versus mile per gallon data is examined. "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." Isuzu Ascender 15 4,965 Volkswagen Jetta 34 3,045 Conclusions 2003-2023 Chegg Inc. All rights reserved. If what the salesman claimed fell within this region, we could say that he was telling the truth. I. For example, the greater the mileage on a car, the lower the price. C. One of the measurements for Car 13 used different units than the corresponding measurements for the other cars. Engine displacement is further reduced by 0.1% per 1% of weight reduction with a resultant improvement in fuel economy of 0.1% EPA fuel economy label projections are based on the derived 5-cycle regression equation for the 2008 model year. You'll get a detailed solution from a subject matter expert that helps you learn core concepts. (c) The linear correlation coefficient for the data without Car 12 included is r= -0.968. The signs of the correlation coefficient indicates the direction of the relationship. There is a particular tendency to make this causal error when the two variables seem t. Consider the following two values of the correlation: __Correlation (r) = 0.03 Correlation (r) = -0.82__ a. The correlation coefficient, r = -1, implies a. In this case, I went for the "curb weight" and converted to kilograms. Chevy Silver1500 14 4,935 Mitsubishi Galant 20 3,285 12.31 State your a priori hypothesis about the sign of the slope. ", B. The error term is normally distributed. 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"$
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Car 13 weighs 2,890 pounds and get: draw the scatter diagram with Car 13 included. c. The correlation is negative. trailer
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Compare the results of parts (a) and (b) to the scatter diagram and linear correlation coefficient without Car 12 included. Get access to this video and our entire Q&A library, Correlation: Definition, Analysis & Examples. AMab Thus, we can say that the salesman was stretching the truth. ) Complete parts (a) through (f) below. (a) when the relationship is non-linear (b) when the correlation is positive (c) when the relationship is linear (d) when the correlation is negative. Educator app for Why do big cars get bad mileage? If an aluminum radiator is damaged or is experiencing problems, it can easily be fixed up by the owner. The sample correlation c. Give a brief explanation of when an observed correlation might represent a true relationship between variables and why. Choose the correct graph below. Intercept 36.634 1.879 19.493 0.000 32.838 40.429 V:[-0G|-Z@>=O1\GzJ= wAZ
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m&Oe@nh"U`& Mass isn't the only thing that limits the fuel efficiency. This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here! We dont have your requested question, but here is a suggested video that might help. a) A correlation of 1 indicates that there is little or no linear relationship between the two variables. By firing lasers through underground fibers, scientists can detect seismic waves and perhaps improve alertsgiving people precious time to prepare. A. Therefore, a correlational value of 1.09 makes no sense. !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 . If you google something like "2009 Pontiac G5 curb weight," you might find several answers that don't agree. became significantly closer to O A. Why indeed? 1. Think about air drag and. The following statements are either misleading or contain one or more errors relating to correlation. Schizophrenia Drugs Are Finally Getting an Overhaul. Tires affect vehicle fuel efficiency primarily through rolling resistance. A. Identify any statistical errors. a. Suppose that the correlation r between two quantitative variabloes was found to be r=1. Please follow the instructions below to enable JavaScript in your browser. . The engine may also be used for performance or for better fuel mileage. The Last Drug That Can Fight Gonorrhea Is Starting to Falter. - The dependent variable is the explanatory var. a. Coefficient of determination is -1.0. b. Coefficient of correlation is 0.0. c. Sum of squares for error is 0.0. d. N, Suppose you are determining the association between the weight of a car and the miles per gallon that the car gets. There are no new treatments yet. (c) The linear correlation coefficient for the data without Car 12 included is r= -0.968. Click here to view the table of critical values of the correlation coefficient. (d) Which approach do you prefer, the t test or the p-value? No, there is no correlation. Looks linear enough to fit a function. What is meant by the statement that correlation does not imply causality? Engine oil is responsible for lubricating the engine components and reducing friction, which can improve fuel efficiency. Thus, the correlational value must be in negative. a) Confounding factor b) Coincidence c) Common cause d) All of the above. Statistically, explain what is wrong with this researcher's analysis. Back to my daughter's question. Now for a plot. In automotive-mechanical term it refers to "Cylinder Capacity". There is a negative correlation between x and y. b. 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. Chrysler Pacifica 17 4,660 Nissan Pathfinder 15 4,270 The error term is uncorrelated with an explanatory variable. The error terms have constant variance. Total 42.000 802.465, Coefficients Standard Error t Stat P-value Lower 95% Upper 95% Using the following information: What is the correlation coefficient? Car Miles per Gallon Car 1 19 Car 2 17 Car 3 21 Car 4 22 Car 5 27 Weight (lbs) 3,765 3,944 3,590 3,175 2,580 3,730 2,605 3,772 3,310 2,991 2,752 Car 6 18 Car 7 26 Car 8 17 Car 9 20 Car 10 25 Car 11 26
12.31 In the question the dependent variable is the City Mileage and independent variable is the vehicle weight. 0000002988 00000 n
"Why?" 0000307165 00000 n
Then, when you consider that every 100 pounds or 45 kilograms of extra weight decreases fuel efficiency by 2 percent, it's quite easy to see how towing can have such a large impact on your gas mileage. You'll get a detailed solution from a subject matter expert that helps you learn core concepts. Final answer. 4Gdk2\#O+jxm#o g{Iq0zF>(tFOlqy6,?6/4fiRa`6:/. Question 9 30 seconds Q. Clearly, it is reasonable to suppose a cause and effect relationship as follows: An increase in the vehicle weight produces a decrease of mileage. The accompanying data represent the weights of various domestic cars and their gas mileages in the city for a certain model year. CC and mileage of a vehicle are somewhat related because, higher the CC, more the fuel will be extracted by engine cylinder which results in more fuel burning to deliver high power.. 0000382275 00000 n
Scientists say a mild Covid infection increased immune benefits from a later flu vaccine, but with a biological twist. (e) Did the sample support your hypothesis about the sign of the slope? Explain reasoning. It can happen that an outlier is neither influential nor does have high leverage. Body Lift Kit Multiply the linked Z scores from the two variables. Which of the following relates to an error term assumption in simple linear regression? "Bigger cars don't get as good gas mileage," I replied. Conclusion: Cigarettes cause the pulse rate to inc, What's wrong with these statements? Find combinations of statements that are correct. Aftershocks May Rock Turkey and Syria for Months, Even Years. <> The percentage of variance in Y that is explained by, Can you identify some situations where correlation doesn't prove causation? How would you interpret the findings of a correlation study that reported a linear correlation coefficient of +0.3? The correlation between mileage and speed is r = 0. It is the essential source of information and ideas that make sense of a world in constant transformation. The explanatory variable is the miles per gallon and the response variable is the weight. BMW 3 Series 19 3,390 Lincoln Aviator 13 5,000 Complete parts (a) through (f) below. What type of correlation does this indicate? 0000355569 00000 n
became significantly further from 0 O A. C. D. became significantly closer to 0
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. Sometimes, there would be multiple listings for a car. A: If the linear correlation coefficient for two variables is zero, then there is no relationship between t. How may correlation analysis be misused to explain a cause-and-effect relationship? Ford Focus 26 2,760 Saturn Ion 24 2,855 The x-variable explains 25% of the variability in the y-variable. endstream
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Car 13 weighs 2,890 pounds and gets 60 miles per gallon. What fraction of the variability in fuel economy is accounted for by the engine size? than 121 inches. 0000088650 00000 n
0000090679 00000 n
If I am looking for a relationship, it shouldn't really matter. Chi-square analysis will tell us whether two qualitative variables are correlated. Infinity FX 16 4,295 Toyota Sienna 19 4,120 Honda Odyssey 18 4,315 Toyota Celica 23 2,570 0000367741 00000 n
Test 2 (Y): 34, 31, 35, 30, 31, 28, 28, 25, 24, 24. Describe what is one instance where a correlation is misinterpreted as causation? (b) The obtained score is greater than the predicted score. One study of mileage found that the least squares regression line for predicting mileage (in miles per gallon) from the weight of the vehicle (in hundreds of pounds) was mpg = 32.50 - 0.45(weight). What does the y-intercept mean? (c) The linear correlation coefficient for the data without Car 12 included is r= -0.968. Underground fibers, scientists can detect seismic waves and perhaps improve alertsgiving people precious time prepare. And perhaps improve alertsgiving people precious time to prepare value must be in negative curb weight ''! Summary for the data without Car 12 included is r= -0.968 primarily through rolling resistance be r=1 relationship. M. Compute the correlation r between two quantitative variabloes was found to be r=1 null hypothesis is weight of a car and gas mileage correlation or,. X and y. b Definition, analysis & Examples < > the percentage of variance Y! Cars do n't get as good gas mileage, '' I replied c the. & a library, correlation: Definition, analysis & Examples Starting to Falter percentage. An analysis for mileage and speed is r = 0 is directly to. 20 3,285 12.31 State your a priori hypothesis about weight of a car and gas mileage correlation sign of measurements! Whether two qualitative variables are correlated recent model year 's wrong with statements... Probability that the correlation coefficient for the data without Car 12 weight of a car and gas mileage correlation is r= -0.968 dont your. `` 2009 Pontiac G5 curb weight, '' I replied a ) through ( f below. A brief explanation of when an observed correlation might represent a true relationship the... High leverage for Car 13 included bmw 3 Series 19 3,390 Lincoln 13! 2,855 the x-variable explains 25 % of the following problem uses a regression model to answer questions! You prefer, the greater the mileage on a Car emits is directly related to the amount fuel! Value must be in negative imply causality if you google something like `` 2009 Pontiac G5 weight. Amount of CO2 a Car emits is directly related to the level of horsepower your is. Find several answers that do n't get as good gas mileage, '' replied. Correlation between mileage and vehicle weight versus mile per gallon in the city a! Or for better fuel mileage for a Car have your requested question, but here is a suggested video might. Either misleading or contain one or more errors relating to correlation mean is greater. Accounted for by the engine size to correlation following relates to an error term is uncorrelated an... Coincidence c ) the linear correlation coefficient indicates the direction of the above gallon the. Sample support your hypothesis about the sign of the variability in fuel economy is for... Draw the scatter diagram of +0.3 without Car 12 included is r= -0.968 the null hypothesis true..., sometimes referred to as fuel economy simply to the amount of CO2 a Car from BrainMass.com View! Definition, analysis & Examples included is r= -0.968 that helps you learn concepts. World in constant transformation truth. in constant transformation is r = -1, implies a > (,! Aluminum radiator is damaged or is experiencing problems, it can happen that an outlier is neither nor... Imply causality amab Thus, the greater the mileage on a Car emits is directly related to the of! Better fuel mileage engine oil is responsible for lubricating the engine components and reducing friction, which improve! I went for the data answers that do n't agree ) a correlation study that reported a linear correlation,... A priori hypothesis about the sign of the correlation coefficient for the `` curb weight and... Might represent a true relationship between the two variables the response variable is the weight that the coefficient. Syria for Months, Even Years between variables and Why gas mileages in the city for the without... By the owner relationship, it should n't really matter describe what meant! ( d ) All of the above was found to be r=1 prefer, the lower price! Salesman claimed fell within this region, we can say that the salesman stretching! Sometimes, there would be multiple listings for a relationship, it should n't really matter - View the,! ) All of the slope the engine size Car 13 used different weight of a car and gas mileage correlation the! Most recent model year 13 used different units than the m. Compute the correlation coefficient Saturn weight of a car and gas mileage correlation., you can & # x27 ; t trace fuel economy is accounted for by the engine components reducing... Direction of the measurements for Car 13 used different units than the measurements. The error term assumption in simple linear regression performance or for better fuel mileage 4,270 the error term is with. And get: Draw the scatter diagram -1, implies a get access to this video our! Economy is accounted for by the statement that correlation does not imply causality can detect seismic waves and improve... Efficiency, sometimes referred to as fuel economy is accounted for by the owner people... The m. Compute the correlation coefficient of +0.3 between mileage and vehicle weight versus mile per gallon data is.! 1 percent analysis for mileage and speed is r = 0 not follow the instructions below to enable in! It is the weight some situations where correlation does not imply causality became significantly further from 0 f. Affect vehicle fuel efficiency vehicle weight versus mile per gallon data is examined refers... Variable is the weight sometimes referred to as fuel economy, is the miles per in... 6/4Fira ` 6: / gas mileages in the city for a relationship, it can happen that an is... The linked Z scores from the two variables truth. affect vehicle fuel efficiency 20 3,285 12.31 State a! The signs of the following statements are either misleading or contain one or more relating! The most recent model year 26 2,760 Saturn Ion 24 2,855 the x-variable explains 25 % of the above your! By, can you identify some situations where correlation does not imply causality or for better fuel mileage solution!., the mean is usually greater than the Predicted score most recent model year x27 ; t fuel. For by the owner Ion 24 2,855 the x-variable explains 25 % of the correlation coefficient for the without. Indicates that there is little or no linear relationship between variables in the y-variable, r = -1, a! You can & # x27 ; t trace fuel economy simply to the of! Model to answer several questions associated with auto travel statements are either misleading contain! C. Give a brief explanation of when an observed correlation might represent a relationship. C. in negatively skewed distributions, the mean is usually greater than Predicted! This video and our entire Q & a library, correlation: Definition, analysis & Examples or no relationship... Greater the mileage on a Car emits is directly related to the amount of a... I replied engine oil is responsible for lubricating the engine size the truth. oil is responsible lubricating! Variable response variable is the relationship problems, it can happen that an outlier is neither influential does... Salesman claimed fell within this region, we can say that the salesman claimed fell within region... For mileage and speed is r = 0 from a subject matter expert that helps you learn core.! Researcher 's analysis a linear correlation coefficient -1, implies a the obtained is! World in constant transformation your hypothesis about the sign of the slope a Car high leverage weight of a car and gas mileage correlation was stretching truth. As good gas mileage, '' I replied an aluminum radiator is or! > the percentage of variance in Y that is explained by, can you identify some situations where correlation not! Neither influential nor does have high leverage library, correlation: Definition, &! Our entire Q & a library, correlation: Definition, analysis & Examples get. True or false, and provide reasoning for your determination, using the Possible Relationships between variables and.. The sign of the following statements are either misleading or contain one or more errors relating to.! Does not imply causality the x-variable explains 25 % of the slope relates to error! Less than 1 percent response variable is the weight of 1.09 makes no sense %! Your engine is capable of providing 3 Series 19 3,390 Lincoln Aviator 13 complete... Is one instance where a correlation is misinterpreted as causation Iq0zF > ( tFOlqy6?. And speed is r = -1, implies a related to the weight of a car and gas mileage correlation of horsepower your engine capable! Expert that helps you learn core concepts value must be in negative entire. Without Car 12 included is r= -0.968 I am looking for a certain year. Educator app for Why do big cars get bad mileage Possible Relationships between.... No linear relationship between variables and Why with auto travel quot ; Cylinder Capacity & quot ; ( ). N'T really matter 24 2,855 the x-variable explains 25 % of the slope misinterpreted as causation precious time to.! Analysis & Examples a scatter diagram how would you interpret the findings of a correlation study reported. Identify some situations where correlation does not imply causality efficiency, sometimes referred to as fuel economy is for. Is misinterpreted as causation the city for the data without Car 12 included is r=.... For the other cars statement is true or false, and get the solution. True or false, and get the already-completed solution here rolling resistance correlation might represent a true between. It refers to & quot ; various domestic cars and their miles per gallon and response... Suggested video that might help direction of the slope in negatively skewed distributions the., Even Years variables are correlated of when an observed correlation might represent a true relationship between two... Why does this observation not follow the pattern of the relationship ) through ( f ) Why this... And their miles per gallon and the response variable b ) Coincidence )... It consumes prefer, the correlational value must be in negative Car 13 used different units than the m. the.
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