Tiger Stripe Copy Center is a small business located near a large university campus. Tiger Stripe Copy offers a range of services to walk-in customers, including passport photos,. self-service copy machines, packaging and shipping, and the sale of course packs. Course packs are bound documents manufactured by Tiger Stripe Copy for purchase by students enrolled in particular classes at the nearby university. A uni- versity instructor usually delivers the original documents or files to Tiger Stripe Copy a few weeks before a semes- ter begins, with students arriving after the start of classes to purchase their copies of that course pack. After delivery of the original materials, the dayshift manager for Tiger Stripe must determine how many copies will sell, to arrange pro- duction of those copies during the busy few weeks before each semester. Historically, Tiger Stripe has used the rule of thumb that a course pack production batch size should be two-thirds the size of the reported enrollment. However, the dayshift manager suspects that a better method of forecasting exists, and began col- lecting more detailed data on course packs and their sales last semester to investigate, shown here in the Course Pack Data table.

The reported enrollment of each course was reported by the instructor, who com- pleted a paper order form at the time of original manuscript drop-off. Thus, these enroll- ment numbers usually represent estimates by the instructor (as the class has not yet started), while actual sales data are exact values recorded by Tiger Stripe Copy. If, in fact, too few copies were made initially, Tiger Stripe was then forced to produce additional copies while customers waited, a process that is both more expensive and hurts Tiger Stripe's reputation for convenience. This past semester, the dayshift manager added two more questions to the bottom of the instructor's order form:

"Is this course pack required or optional for your students?"

"Is this material available through any source other than Tiger Stripe Copy, such as downloadable from the Internet?"

If the instructor answered "optional" for the first question and/or answered yes to the second question, the course pack was marked as yes for Purchase Optional in the data table. Unfortunately, three instructors did not answer the questions at the bottom of their forms, so three courses in the table have no answer for Purchase Optional.

Questions 

1. Use linear regression to investigate the dayshift manager's data and propose an improved methodology to determine course pack production batch sizes. Accord- ing to your method, how many copies should be produced for a course with an estimated enrollment of 35 when the course pack is required? How many should be produced for a course with an estimated enrollment of 275 when the course pack materials are available through an alternate source? 

2. Compare your methodology to Tiger Stripe Copy's historical rule of thumb, using the past data provided here. How much better is your method? Explain. 

3. Identify the three courses whose instructors did not answer the Purchase Optional questions. Based on your previous analysis, what do you think their answers would have been for each of these courses?

Transcribed Image Text:

Course Pack Data from Previous Semester Reported Actual Purchase Reported Actual Purchase Enrollment Sales Optional? Course Enrollment Sales Optional? Course AC 220 220 101 yes MA 110 360 300 no AC 222 210 95 yes MA 112 340 281 AC 225 200 176 no MA 220 300 251 AC 401 100 81 AC 402 38 36 22 no MA 222 280 231 no no no MA 310 250 145 1 AC 405 40 38 no MA 350 250 101 yes BA 100 450 195 yes MA 355 250 91 yes BA 200 400 159 yes MA 420 40 37 BA 330 120 96 no MB 101 250 201 BA 440 42 40 no MB 102 220 180 EC 101 310 244 no MB 444 35 33 2222 no no no EC 201 280 238 no MB 561 35 34 no EC 330 50 46 no RE 335 150 77 yes EC 331 50 50 no WA 100 300 243 EC 335 100 88 no WA 330 120 62 yes ES 330 350 190 yes WA 335 120 49 yes ES 560 50 48 WA 560 50 48 no ES 630 25 25 no 00 WA 610 20 20 00