In: Statistics and Probability
On Saturday morning, Jennifer Bentford received a call at her home from the production supervisor at Bentford Electronics Plant1. The supervisor indicated that she and the supervisors from Plants 2, 3, and 4 had agreed that something must be done to improve company morale and thereby increase the production output of their plants. Jennifer, president of Bentford Electronics, agreed to set up a Monday morning meeting with the supervisors to see if they could arrive at a plan for accomplishing these objectives.
By Monday, each supervisor had compiled a list of several ideas, including a four-day work week and interplant competitions of various kinds. A second meeting was set for Wednesday to discuss the issue further.
Following the Wednesday afternoon meeting, Jennifer and her plant supervisors agreed to implement a weekly contest called the NBE Game of the Week winner and would receive 10 points. The second-place plant would receive 7 points, and the third- and fourth-place plants would receive 3 points and 1 point, respectively. The contest would last 26 weeks. At the end of that period, a $200,000 bonus would be divided among the employees in the four plants proportional to the total points accumulated by each plant.
The announcement of the contest created a lot of excitement and enthusiasm at the four plants. No one complained about the rules because the four plants were designed and staffed to produce equally.
At the close of the contest, Jennifer called the supervisors into a meeting, at which time she asked for data to determine whether the contest had significantly improved productivity. She indicated that she had to know this before she could authorize a second contest. The supervisors, expecting this request, had put together the following data:
Units Produced (4 Plants Combined) |
Before-Contest Frequency |
During-Contest Frequency |
0 – 2,500 |
11 |
0 |
2,501 – 8,000 |
23 |
20 |
8,001 – 15,000 |
56 |
83 |
15,001 – 20,000 |
15 |
52 |
105 days |
155 days |
Jennifer examined the data and indicated that the contest looked to be a success, but she wanted to base her decision to continue the contest on more than just an observation of the data. “Surely there must be some way to statistically test the worth of this contest,” Jennifer stated. “I have to see the results before I will authorize the second contest.”
Requirements (see Rubric on page 8)
Provide Jennifer with a thorough investigation of her problem via the collected data and the design of the test. Because the cost of the program is so high, Jennifer requires very strong evidence of an improvement, so she requires a significance level of 0.01.
PLAN Briefly summarize the objective of the analysis, important variable(s), data collection and characteristics. This should be written as though the reader has no prior knowledge of the problem specifics, but it cannot simply be a “Copy and Paste” of the case problem. State the hypotheses if relevant. State and check required data conditions for any and all statistical methods used. Include all graphs and numerical summary used in this process. |
2 points 2 point 2 points 2 points |
DO Complete the relevant statistical analysis utilizing the pre-programmed statistical software, StatCrunch. Any manual calculation (and there may be none) included must be processed with the Equation Editor. Failure to do so will result in a deduction from the FORMAT points. |
4 points |
REPORT Use the Memo format as shown in the Guided Examples. Your report must begin with a brief summary of the purpose of the analysis and report. Write a brief but comprehensive summary of your findings and conclusion. Include specific numerical information to connect the statistical results with your conclusions. Make your recommendation to Jennifer. Include any qualifications that should be applied to, or reservations you have about the statistical analysis done. |
1 point 1 point 2 points 2 points |