A manufacturer produces a wash-down motor for the food service industry. The company manufactures the motors to order by modifying a base model to meet the specifications requested by the customer. The motors are produced in a batch environment with the batch size equal to the number ordered. The manufacturer has recently sampled 50 customer orders. The motor manufacturer would like to determine if there is a relationship between the cost of producing the order and the order size so that it could estimate the cost of producing a particular size order. The sampled data are contained in the file Washdown Motors.
a. Use the sample data to estimate the least squares regression model.
b. Provide an interpretation of the regression coefficients.
c. Test the significance of the overall regression model using a significance level of 0.01.
d. The company has just received an order for 30 motors. Use the regression model developed in part a to estimate the cost of producing this particular order.
e. Referring to part d, what is the 90% confidence interval for an average cost of an order of 30 motors?