An independent mail delivery service wants to study factors that affect the dail
ID: 2907656 • Letter: A
Question
An independent mail delivery service wants to study factors that affect the daily gas usage of its delivery trucks. Using data collected from different trucks on various days, a company analyst uses a software to fit a regression model of the form y1.6+ 7.2x1-1.4x2+3x3+ 0.07x4, where yvolume of gasoline used (in gallons) x1 weight of truck (in tons) x2= tire pressure (in psi, pounds per square inch) x3 weight of initial package load (in hundreds of pounds) x4 total distance driven while delivering packages (in miles) Answer the following questions for the interpretation of the coefficient of x4 in this model Holding the other variables fixed, what is the average change in daily fuel used for each additional mile that a truck is driven? gallon(s) increase Is this change an increase or a decrease? decreaseExplanation / Answer
here as we can see that coefficient of mile is 0.07
1) therefore holding other variables fixes average change in fuel used for each additional mile =0.07 gallons
2)
is this change an increase or decrease -Increase (as coefficient is positive)