The regional transit authority for a major metropolitan area wants to determine
ID: 3218569 • Letter: T
Question
The regional transit authority for a major metropolitan area wants to determine whether there is a relationship between the age of a bus and the annual maintenance cost. A sample of ten buses resulted in the following data. Click on the datafile logo to reference the data. Age of Bus Annual Maintenance (y Cost 480 950 (a) Choose a scatter chart below with age of bus as the independent variable. (iii) Select yo What does the scatter chart indicate about the relationship between age of a bus and the annual maintenance cost? The scatter chart indicates there may be a Select your answer linear relationship between age of bus and annual maintenance cost, Older buses generally cost more to maintain, and this scatter chart is consistent with what is expectedExplanation / Answer
a) Scatter plot scales are not visible properly but as per i can see, Option (ii) is correct.
The scatter plot indicate that there may be a positive linear relationship between age of bus and annual maintenance cost.
b) The statistical software output for this problem is:
Simple linear regression results:
Dependent Variable: Annual maintanance ($)
Independent Variable: Age of Bus (Years)
Annual maintanance ($) = 220 + 131.66667 Age of Bus (Years)
Sample size: 10
R (correlation coefficient) = 0.93407765
R-sq = 0.87250105
Estimate of error standard deviation: 75.498344
Parameter estimates:
Analysis of variance table for regression model:
Hence,
Regression equation will be:
y = 220 + 131.67 x
c) Both bo and b1 are significant and therefore, they both are not equal to 0.
Parameter Estimate Std. Err. Alternative DF T-Stat P-value Intercept 220 58.480766 0 8 3.7619206 0.0055 Slope 131.66667 17.79513 0 8 7.3990279 <0.0001