A Survey Is Conducted to Determine Whether the Age of Car

question 20

Essay

A survey is conducted to determine whether the age of car influences the annual maintenance cost. A sample of 10
cars is selected and the data is shown below. $$\begin{array} { | c | c | } \hline \text { Age of car (months) } \boldsymbol { x } & \begin{array} { c } \text { Annual Maintenance } \\\text { Cost (\$) } \boldsymbol { y }\end{array} \\\hline 3 & 120 \\\hline 5 & 115 \\\hline 6 & 135 \\\hline 7 & 290 \\\hline 9 & 275 \\\hline 10 & 300 \\\hline 11 & 350 \\\hline 13 & 475 \\\hline 14 & 500 \\\hline 15 & 550 \\\hline\end{array}$$
a. Develop a scatter chart for these data with age of cars as the independent variable. What does the scatter chart
indicate about the relationship between age of a car and the annual maintenance cost?
b. Use the data to develop an estimated regression equation that could be used to predict the annual maintenance
cost given the age of the car. What is the estimated regression model?

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Definitions:

Variable Costing

A costing method that includes only variable production costs (material, labor, and overhead) in the cost of manufactured goods, treating fixed overhead costs as period expenses.

Unit Product Cost

The total cost to produce one unit of product, including direct materials, labor, and allocated overhead.

Net Operating Income

The profit calculated after all operating expenses are subtracted from total revenue but before interest and taxes are deducted.

Ending Inventory

The total value of all inventory a company still has on hand at the end of an accounting period, including raw materials, work-in-process, and finished goods.