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## Problem:The maintenance manager of a large manufacturing company wants to estimate the yearly mainte

Problem:The maintenance manager of a large manufacturing company wants to estimate the yearly maintenance costs of machines. He believes that the maintenance costs (COST, in dollars) is related to the age of the machines (AGE, in months) and the type of machines (type K, type L, and type M). He defines the following indicator variables as follows:K = 1 if a type-K machineK = 0 if not a type-K machineL = 1 if a type-L machineL = 0 if not a type-L machineM = 1 if a type-M machineM = 0 if not a type-M machineThe manager has collected the necessary data as shown on the spreadsheet DATA. Furthermore,he wants to use the following regression model:COSTi 0 1 AGE 2 K 3 L iAnswer the following question:The maintenance manager of a large manufacturing company wants to estimate the yearly maintenance costs of machines. He believes that the maintenance costs (COST, in dollars) is related to the age of the machines (AGE, in months) and the type of machines (type K, type L, and type M). He defines the following indicator variables as follows: K = 1 if a type-K machine K = 0 if not a type-K machine L = 1 if a type-L machine L = 0 if not a type-L machine M = 1 if a type-M machine M = 0 if not a type-M machine The manager has collected the necessary data as shown on the spreadsheet DATA. Furthermore, he wants to use the following regression model: Answer the following question: [1] Show the estimated regression equation. [2] Does the regression equation fit the data well? Explain briefly. [3] Is the model overall significant? Explain briefly. [4] Describe the meaning of estimated regression coefficient of variable AGE in the context of this case. [5] Construct a 95% confidence interval for for B1 and interpret its meaning in the context of this case. [6] Describe the meaning of estimated regression coefficient of variable K in the context of this case. [7] Construct a 95% confidence interval for for B2 and interpret its meaning in the context of this case. [8] The manager wants to find an interval estimate for the average yearly maintenance cost of a population 90-month machines of type-K. Construct that interval and interpret its meaning in the context of this case.