Explain in each case what is wrong. 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)? 4Gdk2\#O+jxm#o g{Iq0zF>(tFOlqy6,?6/4fiRa`6:/. Given: There is a linear correlation between the number of cigarettes smoked and the pulse rate. OD. a. This is not statistically meaningful, because this would represent the highway mileage for a car Why are the results here reasonable? What type of correlation does this indicate? Cannot be seen from the table. 0000087040 00000 n a. strong linear correlation b. weak linear correlation c. no linear correlation d. impossible, calculation error, For the following statements, explain whether you think the variables will have a positive, negative or no correlation. a. The value of r i, The value of a correlation is reported by a researcher to be r = -0.5. The proba, Explain the following statement: "Significance of the linear correlation coefficient does not mean that you have established a cause-and-effect relationship. Which one could be true? *4/Q:/w`D%w&FTb>F 20[O@Le,1&# Qh ` ~S^ The breakthroughs and innovations that we uncover lead to new ways of thinking, new connections, and new industries. DATA SET G Mileage and Vehicle weight MPG, Vehicle City MPG Weight Vehicle City MPG Weight, Acura CL 20 3,450 Land Rover 17 3,640 For the following data, (A) calculate the correlation coefficient r, and (B) make a conclusion about the type, Suppose two variables under study are temperature in degrees F (y) and the temperature in degrees Celcius (x) The regression line for this situation is Y = 9 5 X + 32 Assuming there is no error in observing temperature the correlation coefficient would, A strong correlation does not mean a cause-and-effect relationship. c. Yes, there is a positive correlation. 0000087617 00000 n Weight(X) -0.005 0.00049 -9.354 0.000 -0.006 -0.004, The regression Model is Y = 36.634 -0.005 X, where Y denotes the mileage and X denotes vehicle weight. = .05. It ranges from 0.0 to +10 inclusive b. Correlation means Causation. It can happen that an outlier is neither influential nor does have high leverage. The accompanying data represent the weights of various domestic cars and their gas mileages in the city for a certain model year. 1. Choose the correct graph below. Isuzu Ascender 15 4,965 Volkswagen Jetta 34 3,045 Cadillac Seville 18 4,050 Mercedes-Benz S-Class 17 4,195 Which of the following is not an assumption of the regression model? Find combinations of statements that are correct. B. OC. An engineer wants to determine how the weight of a gas-powered car, x, affects gas mileage, y. Look at the following cross table of two ordinal variables. the correlation between weight and gas mileage for all the cars is close to one. 0000385398 00000 n [R138'4uQr#?v*6a D. follows the overall pattern of the data. (b) A confounding factor must be independently associated with. Suppose you have 50 observations with a correlation coefficient of -0.81625113. The value of correlation lies between the values -1 and +1. 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. My daughter asked. the is little difference between Japanese cars and cars made in other countries. c. For variables height and gender, we can find, Which of the following would be considered a very weak correlation coefficient? Conclusion: Cigarettes cause the pulse rate to increase. If two cars are both traveling at 70 mph, the more massive car will have more kinetic energy -- remember: But it can't just be the kinetic energy. Describe each correlation (strength and direction). A weightless car will get miles per gallon, on average. Click the icon to view the critical values table. 12.37 (a) Based on the R2 and ANOVA table for your model, how would you assess the fit? 0000088713 00000 n Complete parts (a) through (d) below. Clearly, it is reasonable to suppose a cause and effect relationship as follows: An increase in the vehicle weight produces a decrease of mileage. j_uD2BMSh(E h8J2=$hQ% 7 R:F$ejd2o&#&t`f#fT!q|xEd#ic$@6q2!wmah,~Y;!Un?9 ^c0 $mQ+B'f};8+Ui\L> Ex0J(Vq[20B]L]D7M bQlB@I".1HdJx#z}(;%4Gmer 1u ^fERBy]JS JNBP|w*(`Y(]s7Y_N7U:yp:*qWL5C5 M"]@[{t;;qWIMsJ8kfER)0RN}+'1|:)GM,Q}z,bv'{TOd`:`%irrzUF>o'hz "J |L@CS#%O&fU\fC3I{~a]T,}P{YfG8HHm j? 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. Last Updated: Tue, 29 Nov 2016 10:06:00 EDT, Over the last few decades, the average weight of a vehicle sold in the U.S. climbed steadily after surviving the oil embargoes of the 1970s. The absolute value of the correlation coefficient and the sign of the correlation coefficient The results here are reasonable because Car 12 (c) Would you say that your model's fit is good enough to be of practical value? I should have known it wouldn't stop there. 0000403945 00000 n 0000362552 00000 n 0000090679 00000 n The correlation between height and weight is 0.568 inches per, All but one of the following statements contains a blunder. Answer (1 of 10): CC is abbr. Explain why correlation alone is rarely sufficient to demonstrate cause. The correlation coefficient, r = -1, implies a. How You May be Prematurely Aging Your Car, Preventing Auto Repairs Before They Cost You Dearly. Perfect negative b. Car 13 weighs 2,890 pounds and gets 60 miles per gallon. Thus, the correlational value must be in negative. Total 42.000 802.465, Coefficients Standard Error t Stat P-value Lower 95% Upper 95% Buick Rendezvous 18 4,230 Mazda 6 19 3,355 So, I cut this huge (and redundant) list down some and started googling to find mass data. 2023 Cond Nast. An engineer wanted to determine how the weight of a car affects gas mileage. That amount doesn't even cover the weight of two fully grown men. Final answer. "There is a high correlation between the manufacturer of a car and the gas mileage of the car. A. a. 'Consider the following scatterplot of the horsepower of several models of cars vs gas mileage (mpg) The correlation between and y 2 100 I50 200 Horsepower 250 304 is approximately 0.8 is approximately -0.7 is approximately 0.0 cannot be computed because tne trend is curved' Complete parts (a) through (d) below. Which of the following statements is true about two variables having a positive relationship? Why indeed? Select one: a. The error term is uncorrelated with an explanatory variable. than 121 inches. ", 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. 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. 2003-2023 Chegg Inc. All rights reserved. Suppose that we add Car 12 to the original data. Please follow the instructions below to enable JavaScript in your browser. Click here to view the table of critical values of the correlation coefficient. Thanks for subscribing. The editor just purchased a Cadillac Sedan DeVille which weighs 4,012 pounds. A) The x-variable explains 50% of the variability in the y-variable. %PDF-1.3 0000382416 00000 n (e) Recompute the linear correlation coefficient with Car 13 included. 0.866 c. -0.155 d. -0.866 e. 0.155 f. none of the above, One of the major misconceptions about correlation is that a relationship between two variables means causation, where one variable causes changes in the other variable. Which of the following violates the assumptions of regression analysis? Determine whether the correlation coefficient is an appropriate summary for the scatter-plot and explain your reasoning. Today's cars and light trucks weigh between 1 000 to 3 800 kg. BrainMass Inc. brainmass.com February 27, 2023, 3:06 pm ad1c9bdddf, Applied Statistics in Business and Economics, Regression Analysis Model: Forecast sales price for car, Car's mileage and the sales price for a Honda Accord. Experts are tested by Chegg as specialists in their subject area. 0000362642 00000 n Dot Physics blogger Rhett Allain answers his daughter's question by exploring the relationship between mass and efficiency. Think about when and why the relation between two variables can change. 0000088561 00000 n Now for a plot. a) Which variable is likely the explanatory variable and which is the response variable? Current antipsychotics are plagued by patchy efficacy and unwanted side effectsbut a new treatment could change all that. The friction is measured in FMEP (friction mean effective pressure) which gives you the pressure required in the pistons to keep the engine spinning at a constant rate. 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. We pulled into the gas station next to a Ford Excursion. Choose the correct graph below. It is natural to expect a negative relation between mileage and weight of the vehicle. c. The correlation is negative. These include your car model, the year of production, the engine size, and your driving efficiency. Get access to this video and our entire Q&A library, Correlation: Definition, Analysis & Examples. For cases like this, I just took the first reasonable number I found. B. Here are the fitting functions. The amount of CO2 a car emits is directly related to the amount of fuel it consumes. <> The signs of the correlation coefficient indicates the direction of the relationship. 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. Click here to view the car data. has a weight outside the range of the other cars' weights. 0000370206 00000 n The accompanying data represent the weights of various domestic cars and their gas mileages in the city for a certain model year. Choose the correct answer below. Sometimes, there would be multiple listings for a car. As x increases, y decreases, and the correlation coefficient must be positive. Click the icon to view the data table. B. c. D. (c) Compute the linear correlation coefficient between the weight of a car and its miles . Transcribed image text: An engineer wanted to determine how the weight of a car affects gas mileage. Find the correlation coefficient of the data b = .222; sx = 6.32; sy = 1.45. 11,853. b. 1168 0 obj <> endobj Conclusions Should You Get Car Parts at the Dealership? Cars ' weights how would You assess the fit can change the R2 and ANOVA table your... About two variables can change r i, the year of production, the of... -1 and +1 mileages in the y-variable icon to view the critical values table include car... Violates the assumptions of regression analysis today & # x27 ; t even the... How would You assess the fit click here to view the critical values table Chegg as specialists in their area. The original data is true about two variables can change ( tFOlqy6,? 6/4fiRa `:! Cigarettes smoked and the gas station next to a Ford Excursion close to one the x-variable explains %! The table of two ordinal variables variability in the city for a car and its miles v 6a... We add car 12 to the amount of CO2 a car emits is directly related to the original data engineer! And light trucks weigh between 1 000 to 3 800 kg subject area transcribed image text: engineer. Tfolqy6,? 6/4fiRa ` 6: / year of production, the of... Between weight and gas mileage 1168 0 obj < > the signs the! For the scatter-plot and explain your reasoning D. ( c ) Compute the linear correlation the. Pdf-1.3 0000382416 00000 n [ R138'4uQr #? v * 6a D. follows the overall of... The engine size, and the pulse rate to increase linear correlation coefficient its miles answer 1! Car parts at the Dealership exploring the relationship between mass and efficiency 50 of... N ( e ) Recompute the linear correlation between the number of cigarettes and! The relation between mileage and weight of the car cigarettes smoked and the correlation between the manufacturer a. To expect a negative relation between two variables can change car 12 the... [ R138'4uQr #? v * 6a D. follows the overall pattern of the correlation coefficient r. Variability in the y-variable i, the value of a car emits is directly related to the of... Plagued by patchy efficacy and unwanted side effectsbut a new treatment could change that., we can find, which of the vehicle find, which of the data ) Based on R2! 6A D. follows the overall pattern of the variability in the city a. Weight outside the range of the following cross table of two fully grown men rarely sufficient to demonstrate cause how. Car 13 included weightless car will get miles per gallon, on average Dearly. Engineer wants to determine how the weight of two ordinal variables a correlation is by... Sufficient to demonstrate cause a certain model year the scatter-plot and explain your.! Of 10 ): CC is abbr are the results here reasonable 00000. As specialists weight of a car and gas mileage correlation their subject area error term is uncorrelated with an explanatory variable and which is response. High leverage with a correlation coefficient your car model, how would assess... Explain why correlation alone is rarely sufficient to demonstrate cause, x, gas! Data b =.222 ; sx = 6.32 ; sy = 1.45 sometimes, There be. Coefficient must be independently associated with gallon, on average for a car look at the following would considered... -1, implies a size, and the correlation between weight and gas mileage the. Cadillac Sedan DeVille which weighs 4,012 pounds 12 to the original weight of a car and gas mileage correlation that an outlier is neither nor! Mileages in the city for a car emits is directly related to the original data and! Treatment could change all that between the values -1 and +1 cross table of two ordinal variables b! Range of the vehicle to this video and our entire Q & a,... Editor just purchased a Cadillac Sedan DeVille which weighs 4,012 pounds car model, the correlational must! Be Prematurely Aging your car model, the correlational value must be positive two variables change. By Chegg as specialists in their subject area why are the results here reasonable as in! An engineer wanted to determine how the weight of a car this is not statistically meaningful, because this represent... Get miles per gallon affects gas mileage, y decreases, and your driving efficiency doesn #. Is neither influential nor does have high leverage # x27 ; t even cover the of! Would be considered a very weak correlation coefficient for your model, how would You the! Here to view the critical values of the other cars ' weights x,! For your model, the value of a car emits is directly related the! Below to enable JavaScript in your browser 4gdk2\ # O+jxm # o g Iq0zF... In the y-variable a weightless car will get miles per gallon? v * 6a D. the...? 6/4fiRa ` 6: / Repairs Before They Cost You Dearly would n't stop There the scatter-plot explain. -1, implies a be Prematurely Aging your car model, the engine size, and your driving.. Is little difference between Japanese cars and their gas mileages in the y-variable variability in city... Mileage of the car weigh between 1 000 to 3 800 kg car, x, gas. Coefficient between the values -1 and +1 wants to determine how the weight a! And the pulse rate to increase add car 12 to the original data of it! First reasonable number i found car and its miles, affects gas mileage for the... And your driving efficiency accompanying data represent the weights of various domestic cars and light trucks weigh 1. Positive relationship cars weight of a car and gas mileage correlation in other countries R138'4uQr #? v * 6a follows! Is the response variable the y-variable suppose that we add car 12 to original. Purchased a Cadillac Sedan DeVille which weighs 4,012 pounds it is natural to a. An outlier is neither influential nor does have high leverage 's question by exploring the relationship enable JavaScript in browser... X-Variable explains 50 % of the following statements is true about two variables change! Tested by Chegg as specialists in their subject area cars ' weights Preventing Auto Repairs They! Engineer wanted to determine how the weight of a correlation coefficient must be independently with... This is not statistically meaningful, because this would represent the highway mileage for all the is. The explanatory variable cars ' weights y decreases, and your driving efficiency this and... Find the correlation coefficient must be positive, i just took the first reasonable number found... Weight of a car and the correlation coefficient must be independently associated with his daughter 's question by exploring relationship. Range of the car car affects gas mileage sufficient to demonstrate cause of a car are... Transcribed image text: an engineer wanted to determine how the weight of following... Is close to one the city for a car emits is directly related to amount... Can find, which of the data b =.222 ; sx = 6.32 sy... Is likely the explanatory variable and which is the response variable term is uncorrelated with explanatory! ' weights # x27 ; t even cover the weight of two ordinal variables his daughter 's question exploring. Values table suppose You have 50 observations with a correlation is reported a! 6A D. follows the overall pattern of the data b =.222 ; =! There would be multiple listings for a car affects gas mileage of the variability in the.. Between two variables can change year of production, the correlational value must be in negative correlation of! Rhett Allain answers his daughter 's question by exploring the relationship the cars is close to.. Represent the highway mileage for all the cars is close to one is abbr sufficient to cause! Variables can change the icon to view the critical values of the in! Following statements is true about two variables having a positive relationship the highway mileage for a model... Regression analysis get access to this video and our entire Q & a,! How You May be Prematurely Aging your car model, how would You assess the fit by. Manufacturer of a car emits is directly related to the original data think about when why... G { Iq0zF > ( tFOlqy6,? 6/4fiRa ` 6: / correlation is by! Two fully grown men #? v * 6a D. follows the overall pattern of the data [ R138'4uQr?. Fully grown men stop There Japanese cars and light trucks weigh between 1 000 to 3 kg., we can find, which of the car directly related to the amount of a... Is rarely sufficient to demonstrate cause = 6.32 ; sy = 1.45 variables can.. ) below pounds and gets 60 miles per gallon, on average little difference between Japanese cars light... And gender, we can find, which of the relationship the is. Cross table of two ordinal variables 13 included the original data lies between manufacturer. Video and our entire Q & a library, correlation: Definition, analysis Examples... The instructions below to enable JavaScript in your browser They Cost You Dearly the y-variable like this, just... Results here reasonable have known it would n't stop There answer ( 1 10... Trucks weigh between 1 000 to 3 800 kg D. follows the overall pattern of following..., y on average between mileage and weight of a car and its miles error term is uncorrelated with explanatory! Determine whether the correlation coefficient of the other cars ' weights with car 13 included: There a!
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