Q1
Develop a multiple regression model with categorical variables that incorporate seasonality for forecasting sales using the last three years of data in the Excel file New Car Sales.
Q2
Data in the Excel File Microprocessor Data shows the demand for one type of chip used in industrial equipment from a small manufacturer.
a) Construct a chart of the data. What appears to happen when a new chip is introduced?
b) Develop a regression model to forecast demand that includes both time and the introduction of a new chip as explanatory variables.
c) What would the forecast be for the next month if a new chip is introduced? What would it be if a new chip is not introduced?
Q3
Using the data in the Excel file Student Grades, construct a scatter chart for midterm versus final exam grades and add a linear trendline. What is the regression model? If a student scores 70 on the midterm, what would you predict her grade on the final exam to be?
Q4
The managing director of a consulting group has the following monthly data on total overhead costs and professional labor hours to bill to clients.
a) Develop a trendline to identify the relationship between billable hours and overhead costs.
b) Interpret the coefficients of your regression model. Specifically, what does the fixed component of the model mean to the consulting firm?
c) If a special job requiring 1,000 billable hours, what would the overhead costs be?