mathx.com Take a Test Shaquaille Simpson Quizzes and Tests QMTH 210 Section 002
ID: 3180390 • Letter: M
Question
mathx.com Take a Test Shaquaille Simpson Quizzes and Tests QMTH 210 Section 002 Shaquaille Simpson & 3/23/17 6:01 PM Submit Quiz Quiz: Chapter 8 Quiz This Quiz: 3 pts possible 2 of 3 (0 complete) v This Question: 1 pt Aner keeping of his heating expenses for several winters, a homeowner believes he can estimate the track monthly cost from the average daily Fahrenheit temperature using the model cost 91 temp. The residuals plot for his shown. Average Temperature a) Interpret the slope of the line in this context. What does the model predict given a 1" increase in temperature? O A. The model predicts a $127 increase in heating cost. O B. The model predicts a $1.91 decrease in heating cost, O C. The model predicts a $1.91 increase in heating cost. O D. The model predicts a $127 decrease in heating cost. b) Interpret the y intercept of the line in this context. What does the model predict given a temperature of 0°? O A. The model predicts a heating cost of $0. O B. The model predicts a heating oost of S1.91. O C. The model predicts a heating cost of s127 cyDuring the months when the temperature stays around freezing (32 F) would you expect the cost predictions based on the model to be accurate, too low, or too high? Explain. O A Acourate, because the predicted and observed values are very close O B. Too high, because the residual is negative O c. Too low, because the residual is positive. d) What heating cost does the model predict for a month that averages 10°? Click to select your answer(s).Explanation / Answer
a) Given regression equation is Cost = 127 -1.91temp
The cost decreases by $1.91 per degree of average daily temperature starting from a value of 127 degrees.
Option B.
b) The y-intercept indicates that if the average daily temperature for a given month is zero degrees C, then expected costs will be $127.
Option C.
c) Remember, the theoretical form of the model is: Cost = 127 – 1.91Temp + e.
According to the plot of the residuals, e tends to be negative when average daily temperature is around 32 degree Fahrenheit. This indicates that the model is biased upwards and tends to overestimate costs. You would thus expect your bill to be a bit lower than the model predicted.
Option B: Too high because the residual is negative
d) Cost = 127 – 1.91(10) = $107.9
e) Actual Cost = 127 - 1.91(10) + 4 (the residual associated with 10 degrees C) = 111.9 = $112
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.