1. (10 points) - Buservice Inc. is a transportation company in the Tampa area that provides bus services. Twelve months ago, Buservice Inc. initiated a project with the intent of reducing the annual maintenance cost, with an experiment executed with two identical new buses. Bus #32 had the TRADITIONAL preventive maintenance program executed as usual, while Bus #33 had the NEW preventive maintenance program in the first 12 months of its life. The 12-month project was just completed this week and the following table was put together to present the monthly maintenance cost for the first 12 months for both buses: a) ( 1 point ) - Create a descriptive statistics analysis in Excel at 95% confidence level for the maintenance cost data for Bus \#32 and Bus \#33. Use the output form the descriptive analysis tool and compare average, standard deviation and coefficient of variation between Bus #32 and #33. UPLOAD THE EXCEL SPREADSHEET FOR THIS CALCULATION IN ORDER TO GET POINTS FOR THIS TOPIC. b) ( 1 point) - Use the output from the descriptive statistics analysis in topic (a) and create a confidence interval for 95% confidence level for the monthly maintenance cost for Bus \#32 and \#33. UPLOAD THE EXCEL SPREADSHEET FOR THIS CALCULATION IN ORDER TO GET POINTS FOR THIS TOPIC. c) ( 1 point) - Create a Scatter Chart with the monthly maintenance cost y-axis and month \# on x-axis for both buses. Include axis title and chart title. What is your analysis of this chart? Discuss in detail. UPLOAD THE EXCEL SPREADSHEET FOR THIS CALCULATION IN ORDER TO GET POINTS FOR THIS TOPIC. use Excel to develop an estimated linear regression equation to predict the monthly maintenance cost in the first 12 months for other buses with the same preventive maintenance program. (1 point) What is the estimated linear relationship as: Ym=bc+b1X, where Y is the monthly maintenance cost and X is the month \#. What are the values of bn and bi ? (1 point) What is the value of R-square for this linear regression and how do you interpret the R-square value? (1 point) Use the estimated linear relationship to calculate the estimated maintenance cost for month \#13. If the actual maintenance cost for month \#13 ended up being $10,000, calculate the forecasting error for that month. UPLOAD THE EXCEL SPREADSHEET FOR THIS CALCULATION IN ORDER TO GET POINTS FOR THIS TOPIC. e) Use the monthly maintenance cost data for Bus \#33 provided and use Excel to develop an estimated linear regression equation to predict the monthly maintenance cost in the first 12 months for other buses with the same preventive maintenance program. (1 point) What is the estimated linear relationship as: Y==b9+biX, where Y is the monthly maintenance cost and X is the month \#. What are the values of b0 and b4 ? ( 1 point) What is the value of R-square for this linear regression and how do you interpret the R-square value? (1 point) Use the estimated linear relationship to calculate the estimated maintenance cost for month \#13. If the actual maintenance cost for month \#13 ended up being $6,000, calculate the forecasting error for that month. UPLOAD THE EXCEL SPREADSHEET FOR THIS CALCULATION IN ORDER TO GET POINTS FOR THIS TOPIC. f) (1 point) Calculate the reduction in maintenance cost for every month, create a scatter diagram and discuss if there is a linear relationship between the monthly cost reduction for the first 12 months. If yes, calculate R-square. Based on the analysis of the scatter diagram is the reduction in monthly cost stable month-bymonth? UPLOAD THE EXCEL SPREADSHEET FOR THIS CALCULATION IN ORDER TO GET POINTS FOR THIS TOPIC
