Needing help with Statistics Homework!!!
Unit 8 - Section 4.2
1. If the linear correlation between Choose the correct answer below. O A. Positive O B. Negative O C. More information is needed An engineer wants to determine how the weight of a gas-powered car, x, affects gas mileage, y. The accompanying data re e weights of various domes Click here to view the weight and gas mileage data (a) Find the least-squares regression line treating weight as the explanat and miles per gallon as the response variable. (Round the x coefficient to five decimal places a al places as needed. Round the constant to two decimal places as needed.) (Use the answer from part a to find this answer.) low and fill in any answer boxes in your choice. to interpret the y-intercare " mile(s) per gallon, on average. It is not appropriate O B. For every pound added to the w get und added to the weight of the car, gas miles per gallon, on average. O C. A weightless car will get miles per gallon, on average. It is no propriate to interpret the slope O D. It is not appropriate to interpret the slope or the y-intercept. IC) A certain gas- average for cars of this O Bel O Above (d) Would it be reasonable to use the least-squares regret allon of a hybrid gas and electric car? Why or why not? O A. No, because the absolute value of the correlation O B. No, because the hybr different type of car. O C. Yes, because the absolute value of the correlation coefficient O D. Yes, because the hybrid is partially powered by gas critical value for a sample size of n = 11. 1: Car Weight and MPG large state university. Complete parts ( a) through () below exam score, y, for a san " Click the icon to view a table of critical values for the correlation coefficient (a) Find the least-squares regression line treating number of absences as the explanat the response variable. Round to three decimal places as needed.) (b) Interpret the slope and the y-intercept, if appropriate. Choose the correct answer below and fill in any answer boxes in your choice. (Round to three decimal places as needed.) O A. For every additional absence, a student's final exam score drops points, on average. The average final exam score of students who miss no classes is O B. For every additional sence, a student's final exam score drops points, on average. It is not appropriate to inter y-intercept. O C. The average final exam of students who miss no classes is . It is not appropriate to interpret the slope. O D. It is not appropriate to interp erpret the slope or the y-intercept. (c) Predict the final exam score for a student who misses five class periods. decimal places as needed.) Compute the residual. places as needed.) Is the final exam score above or below average for this number of absences? O Abov O Below (d) Draw the least-squares regres ion line on the scatter diagram of the data. Choose the correct graph below. OA. Exam Scores vs. Absent O B. Exam Scores vs. Absences 1 . . .... Q Number of Absences Oc. OD. Exam Scores vs. Absences (e) Would it be reasonable nal exam score for a student who has missed 15 class periods? Why or why not O A. No, because the absolute value of the correlation coefficient is less the e critical value for a sample size of n = 10. O B. No, because 15 absences is outside the scope of the model. O C. Yes, because the purpose of finding the regression line is to make predictions outside the scope of the model. O D. Yes, because the absolute value of the correlation coefficient is greater than the critical value for a sample size of n = 10. 2: Absences and Final Exam Scores x 0 6 7 exam score, y 88.3 85.4 84.4 821 77.4 73.5 63.9 71.4 652 65.5 3: Critical Values for Correlation Critical Values for Correlation Coefficient 0.997 0.632 0.602 0576 0.553 0.532 0.514 0.497 0.482 0468 0374 0361 The data in the table represent the number of licensed drivers in various age g Click the icon to view the response variable. Repeat this procedure for females and the number of fatal crashes. y. as the Find the least-squares regression line for males. ( Round the * coefficient to three decimal places as needed . Round the co arest integer as needed.) Find the least-squares regression line for females. (Round the x coefficient to three decimal places as needed. Round the constant to the nearest integer as needed.) (b) Interpret the slope of the least-squares ion line for each gender, It app What is the correct interpretation of the slope of the least-squares regressi ales? Select the correct choice below and, if necessary. fill in the answer box (Use the answer from part a to find this answer.) O A. If the average age of all male licensed drivers increases by 1, then the number of fatal crashes increases by on average . O B. If the number of male licensed drivers increases by 1 (thousand), then the number of fatal crashes increases by . on average O C. If the number of fatal crashes increases by 1, then the number of male licensed drivers increases by thousand, on average. O D. It does not make sense to interpret the slope. to complete coffe fine O A. If the number of fatal crashes increases by 1, then the number of female license thousand, on average O B. If the average age of all female licensed dri tal crashes increases by O C. If the number of female licensed drivers increases by 1 (thousand), then the number of fatal crashes increases by on average. O D. It does not make sense to interpret the slope. The slope of the regression line for male - that for fem nsurance company may use this information to argue for (3) below averagem ber of fatal accidents for 16 to number of fatal accidents for males greater than 74 years old above or below average? How might an insurance company use this below average? was the number of fatal accidents for males gre The number of fatal accidents for 16 to 20 year old males was (4) - cidents for males greater than 74 years old was (6)_ An insurance company could use it to argue for higher rates for (7) drivers and lower rates for (8)- Does the same relationship O No Ye 1: Data for licensed drivers by age and gender Number of Male of F Number of Female Fatal Age Drivers (000s) Licensed Drivers Cras 36- 20 5:424 5:180 6.816 20 406 19.898 ESE'FI 4 903 2:022 8.376 5 375 (1) O the same as more fatal crashes than ( higher rates for female customers 4) O above average. less than O as many fatal crashes as O equal rates for male and female customers 5) O above average. (6) O above average. O below average. O below average. (7) O younger (8) O younger O older What is a residual? What does it mean when a residual is positive? swer below. O A. A residual is the difference B. Aresidual is the differ then the response variable is gre O C. A residual is the difference between an obs OD. Aresidual is andice sidual is a data point that does not fit the pattern of the
