IME 301 Chapter 6 Homework and Supplemental Information:
Revised 1/11/13

Assignment #1:

Problems 6-2, 6-4 , 6-6 , 6-19 (Ignore the question in the book, but use the data to complete the following:

6-19a. Calculate the mean, variance, standard deviation, range, 1st, 2nd, and 3rd quartiles of the data set by hand showing the formula and using a calculator. You can use built in calculator functions if they are available. Use the textbook method to find the quartiles as described on page 201).

6-19b. Manually construct a histogram of the data using whatever number of intervals and equal interval widths you feel is appropriate. Label the bins and axes.

6-19c. Construct a Box and Whisker plot by hand based on your results from part a.

6-19d. Now use Excel or Minitab to duplicate parts a, b, and c. To make box plots with excel, you can use the box plot utility provided in the "Documents & Video Clips" folder. CLEARLY LABEL ALL OUTPUT AND PUT IN SEQUENTIAL ORDER. Do not just say:: SEE ATTACHED

6-19e. Analyze your results from parts a, b, c, and d and comment on which descriptive statistics you thing gave you the most information about the data. What issues did you see in the data?

6-65 (MINITAB or Excel) Make Side by side box plots (four plots) for the data provided using the Excel Utility or Minitab. Analyze the results and discuss the usefulness of the box plots.


AGAIN NOTE: Please turn in homework AND computer printouts in the order assigned with each problem, page, and graph clearly labeled. DO NOT simply put all the graphs at the back and say "see attached". This instruction is very important toward keeping the instructor sane and in the mood to give full credit.

Supplemental Video Clips (.avi files) are available to explain many of the topics in IME 301. You can download the video clips below. Note that you also need to download and install the TSCC.exc codec in order to view the video clips.

TSCC.exe - Codec must be installed to run video clips. Video clips are .avi files
Introduction to Sampling - Relationship between a population and a sample (ppt file)
Histogram Construction using Excel - How to make histograms using Excel
Sturges Rule - Choosing the optimal number of bins for a histogram
Boxplots - How to construct a boxplot if you know the quartiles (ppt file)
Binwidth Demo - An applet is used to show the impact of changing bin width on a histogram

Optional: Relevant video clips from Introduction to Business Statistics by Weiers
Basic Statistics - mean, median, mode, variance, standard deviation, quartiles (ppt file)
Descriptive Statistics 1 - data arrays, frequency distributions, historgrams, Sturges Rule (ppt file)
Descriptive Statistics 2 - scatter diagrams (ppt file)
Descriptive Statistics 3 - example showing construction of various descriptive statistics (ppt file)

Chapter 6 Reading Notes:

It is very important that you read chapter 6. It is well written and helps you establish a good foundation for the course and the data collection project.

In my experience, histograms, bar charts (and a very useful version called the Pareto Chart shown on page 688), and box plots are the work horses for data presentation. Pie charts are not as useful as they seem because are more difficult to read than a bar chart, especially during a PowerPoint presentation. Note that Pareto Charts are widely used in the world of quality and “continuous improvement.”

Histograms – Making histograms is an art. I have supplemented the course here. Note that making histograms using Excel is not easy.

Box Plots – Probably one of the best ways to represent data graphically. See the supplemental video clip which explains how to make a proper box plot.

Supplemental Video Clips: Boxplots

Sample Statistics

Sample Mean – Most widely used sample statistic and is called x-bar ( ).

Sample Median – Very widely used to describe the center of a population. Is not sensitive to the impact of extreme values

Sample Trimmed Mean – Not widely used, but is usually between the mean and median. You do see in athletics where they discard the high and low judge’s scores and average the rest.

Sample Mode – Another type of average, but not widely used.
Sample Variance – The square root of the variance is called the Standard Deviation. These two sample statistics are the workhorse statistics for describing variation. You must know how to calculate these sample statistics!!

Sample Quartiles (particularly quartiles) – There are many ways to compute quartiles. Minitab and Excel, for example, give different results. The textbook method is what Minitab uses. We need quartiles to develop box plots. Learn the definition of “inter-quartile range.” Note that software programs vary in the algorithms used to define quartiles.