Bus Q600 classes in Week 8

Dear Bus Q600 students;


Please note that Bus Q600 classes will NOT be cancelled during Week 8 (Nov. 2-4). We will continue with the discussion of Chapter 7 which was started this week.

Good luck in your upcoming exams (accounting and economics).

Summary for Week 7 (October 26-28)

We started with a (detailed) review of the stock returns problem and looked at the n=2 and n=3 sample cases. In all cases we have the mean of the sample averages equal to the population mean, and the variance of the sample averages equal to the variance of the population divided by the sample size.

We discussed the adjustment necessary in the standard deviation of the sample means if the population is finite and sampling is done without replacement. Next, we looked at the MPG of Zebra 501 GT sports car using Visual Statistics (that comes with the book CD). The concepts of unbiasedness and minimum variance estimators were discussed. We continued with the example of a Mercury speed boat engines.

The chapter ended with the discussion of sample proportion which was motivated using the disastrous "New Coke" campaign in 1985.

The new Chapter 7 was introduced by an example involving the taxable incomes of physicians where μ is not known but σ is known. We will continue with this example next week.

Lost accounting textbook

Dear Bus Q600 students; I received the following e-mail from Vijay who has lost his book. Please contact him if you have found it.

``Hello Dr. Parlar,
My name is Vijay Somers and I am in your evening Q600 class on Tuesday.  I believe I may have lost my accounting(A600) textbook in RJC214 last Tuesday.  Is there anyway you could send out an email to the class to see if anybody picked it up by accident? 

Thanks,
Vijay Somers''

Summary for Week 6 (October 19-21)

We continued our apple juice can example where the content of the cans was uniformly distributed between 950mL and 1050mL. We calculated the probability that a randomly selected can had between 980 and 1020 mL of apple juice by simply finding the area of a rectangle.

In Section 5c, normal distribution was introduced. I illustrated this distribution by using data sets of heights and exam results. We also looked at some web sites describing Galton's board which illustrates the principle that binomial converges to the normal.

This chapter ended with a discussion of probability calculations which became possible by converting the X r.v. to a standardized Z r.v. We also analyzed the reverse problem of calculating the z-values, given the probability.

Chapter 6 is concerned with sampling distributions and the first topic discussed here was the distribution of the sample mean. We started a detailed example of four groups of stocks and compared its probabilistic properties to the properties of the sample mean and its distribution.

We will continue and finish Chapter 6 in Week 7.

Please use your mcmaster.ca e-mail accounts when corresponding with McMaster faculty

Dear Bus Q600 students:

It is important to use your mcmaster.ca e-mail accounts when you correspond with me and other instructors. If I receive an e-mail from a student's Gmail, Yahoo!, etc., account, I may not respond to that e-mail.

McMaster Policy: ``Students who wish to correspond with instructors directly via email must send messages that originate from their official McMaster University email account. This protects the confidentiality and sensitivity of information as well as confirms the identity of the student.''

Assignment 3 due dates

Please see this link for Assignment 3 information and the due dates.

Summary for Week 5 (October 12-14)

 We returned to the tire molding example (where tires are molded in pairs), and introduced the concept of a probability distribution (a list of possible values the random variable can take and their corresponding probabilities). In this example we calculated the average number of defectives that one may find as a result of 100 runs (where each run produces two tires).

The concept of the expected (mean) value of a random variable X was formalized with a formula and illustrated with a physical analogy, i.e., the centre of gravity. Discussion continued with an important example of home insurance policy where even though the expected profit for the company is positive, it may not be desirable to stay in business if the company insures only a few homes.

We then learned about the variance of a random variable and compared its formula to the formula we used for a population's variance. Three simple examples involving a coin flip were used to illustrate the case of increasing variance and zero variance (loaded coin).

We looked at the important special discrete distribution known as binomial and calculated the probability of getting x successes in n trials. (I illustrated this with three tennis balls and a bucket.) We ended Chapter 4 with an application of binomial distribution to a new drug purchase problem which hospital boards may face.

Since Chapter 4 is now complete, due dates for Assignment 2 are during Week 6, see http://www.business.mcmaster.ca/courses/q600/Assignments/HW2/HW2.html

Chapter 5 is concerned with continuous random variables (such as waiting time, amount of apple juice in a can, or temperature). I illustrated the concept of a continuous random variable with a YouTube video of a bottle filling process. We then looked at the special case of a uniform random variable using the example of the random content of an apple juice can.

The lecture notes for Week 5 (the Thursday section C02) are here.

We will continue with Chapter 5 and finish it during Week 6.

Assignment 1 marks (adjusted)

I noticed that the the solution for Q8.4 (population standard deviation) did not print correctly, thus resulting in the erroneous marking of this question. The correct value is 73.829.

In order not to penalize the students who gave the correct answer, I have decided to increase everyone's mark by 1.

See the results at, http://www.business.mcmaster.ca/courses/q600/documents/Q600-2010-101013-MP-Posted.pdf.

Informal Course Evaluations

Dear Bus Q600 students:


Thank you for the frank and constructive comments you provided on the informal evaluation that took place during Week 4. I am pleased to report that a large majority of you were happy with how the course was being delivered. There were a few isolated complaints and several suggestions; I will try to implement some minor changes based on these comments.

I analyzed the ratings you provided for Question 3 (The Effectiveness of the Instructor) and found that in all three sections the median score was 9. This is very encouraging, and I hope that you will find the course even more interesting as we cover new topics in the coming weeks.

Assignment 2 due dates

• Section EC01 : October 19, 2010 (Tue.) 7:00 pm (in class)
• Section C01 : October 20, 2010 (Wed.) 2:30 pm (in class)
• Section C02 : October 21, 2010 (Thu.) 11:30 am (in class)

Please, also remember the following:

• Put your section number, your name and your student number on the top right-hand corner of the cover page/first page of your assignments. This is crucial for easy sorting into alphabetical order and by section.
• The assignments can be hand-written (except where you have an Excel/MegaStat output in which case you must also submit the hardcopy output). 
• Provide your explanations in full sentences, not in point form. 
• You must submit your assignments at or before the due date/time indicated for your section. 
• Late assignments will not be accepted
• Please note that the assignments e-mailed to Dr. Parlar or to any of the TAs will not be accepted.

Summary for Week 4 (October 5-7)

We started by reviewing last week's material. We then defined an "event" and discussed the method of calculating the probability of an event.

Next, complement, union and intersection of events was discussed and used in an example of newspaper readership. The formula for the probability of a union of two events was presented and mutually exclusive events were also defined.

Discussion continued with the definition of conditional probability which was used in the analysis of the problem involving hiring of management trainees.

Independent events were introduced and related to the results in the trainees example. This completed Chapter 3.

We started Chapter 4 by discussing random variables which associate numerical values with the outcomes of an experiment. Several examples were discussed that involved discrete and continuous random variables. As the last example we looked at a tire molding problem where there were four outcomes but three values for the random variable (defectives in the pair).

In this class the students also provided their comments on the informal course evaluation. I will say more about this in a different post.

Summary for Week 3 (September 28-30)

We started by reviewing the Empirical Rule and the related concept of Tolerance Intervals and 6-sigma. We continued with a discussion of the "z-scores." ("zed", not "zee".) We made use of the Tolerance Interval idea by looking at an example of quality improvement, i.e., the coffee temperature case.

Next, we looked at another measure of variation, namely, the pth percentile. We illustrated this concept by discussing two examples with n = 8, and n = 7. The calculation of the percentile was formalized by introducing a rule that involved two steps. We completed Chapter 2 with a discussion of the Box-and-Whisker plots.

The new Chapter 3 (Probability) was motivated with examples of coin toss, Lotto 6/49, the birthday problem, and Monty Hall's car-and-goats problem. We then looked at three methods for calculating probabilities. Next, a random experiment was defined and this was followed by sample spaces and events which were illustrated using the coin tossing and backgammon examples.

I hope you found the YouTube videos and the car-goats problem interesting.

We will continue with Chapter 3 (and finish it) next week.