Statistics Detective Review Lab
Recall that an underlined phrase means that it is a link off of the web page itself. The lab can be accessed from
http://www.cs.appstate.edu/~sjg/class/1010/wc/stats/detectives03.html
Use the clues and Excel calculations in order to eliminate people in the class, until you are down to one person. To mark off eliminated people on the computer, click on the row number (in grey) and then click on B on the formatting toolbar (if you don't see this then make sure it is checked under View/toolbar/ formatting)
Here are some Excel commands to help you:
  • The average of data in column G, with numerical entries in rows 2 thru 46, would be     =average(g2:g46)
  • The median of the data in column g would be       =median(g2:g46)
  • The lo of the data (the 0th quartile) in column g would be       =quartile(g2:g46,0)
  • The first quartile, q1, of the data in column g would be       =quartile(g2:g46,1)
    and so on for the other numbers in the "5 number summary".
      Use the clues below and effective reasoning skills in order to identify the "odd person out" in our class data set.

      Thue suspect...

    1. hits the 1st or 3rd quartile (q1 or q3) on the "head" for the number of competitors of the family bathroom (compute these and write them down here)
    2. on this histogram of the number of seconds that breath was held, falls within the most common class range ("a" less than or equal to breath held less than "a" + 10)
    3. falls within the middle 50% of the class on this boxplot of the distance from home
    4. pulls this regression line for "does height predict armspan" down since the actual armspan value corresponding to the actual height is below the predicted value for the actual height given by plugging into the linear regression equation.
    5. hurts the statistics that show that, on average, women perform more poorly than men on the timed test, but confirms the statement that (even though it was not true for our class), on average, women do just as well on the untimed test. (Recall from a previous lab that the female average for our class on the untimed test was 1.5, while the male average was 1.89, and the female average for the timed test was 1.67, while the male average was 2.)
    6. has an exact golden mean of (1+sqrt(5))/2 embedded in the forearm to hand ratio when the numbers are rounded to one decimal value.
      Compute the golden mean rounded to one decimal value.
      In Excel, compute the forearm to hand ratios of the remaining suspects and use the clue to eliminate people.
      How many additional people have been eliminated?
      How many total people have been eliminated?
    Your Approved Suspect Once you have your guess, call me over and show it to me, and have your suspect approved. Wait until your guess has been approved BEFORE you write it down here:

    Gender______   Height______   Armspan______   Foot Length______   Head Circ______ Hand______  

    Forearm______   Smoker______   Class_________________   Siblings______   Home_______  

    Major_______________________   Minute______   RealWds______   NonsenseWds______  

    Breath______   Timed MRT______   Untimed MRT______  

    Verification of the Clues
    Explain why each clue is satisfied by your approved suspect. There is NO need to explain whether other classmates do or do not satisfy the clues - you only need to address your approved suspect. Give detail that conveys deep understanding of the statistical representations that are involved. This means that you will have to include Excel computations in your explanations and that you should explain calculations and graphs in depth to show how you can see that your suspect satisfies the related clue. Your lab grade for today will be based on the depth, quality and clarity of your responses. This is also a good review so you should look up any statistical representations that you do not understand. Skim through the major writing assignment directions at the end of this lab before you answer the following.

    I will explain in depth why my suspect



    1. is not one of the values dragging the mean above the median on this bargraph of the number of nonsense words remembered (compute the mean and median and write them down here)

















    2. hits the 1st or 3rd quartile (q1 or q3) on the "head" for the number of competitors of the family bathroom (compute these and write them down here)

















    3. on this histogram of the number of seconds that breath was held, falls within the most common class range ("a" less than or equal to breath held less than "a" + 10)

















    4. falls within the middle 50% of the class on this boxplot of the distance from home

















    5. pulls this regression line for "does height predict armspan" down since the actual armspan value corresponding to the actual height is below the predicted value for the actual height given by plugging into the linear regression equation.

















    6. hurts the statistics that show that, on average, women perform more poorly than men on the timed test, but confirms the statement that (even though it was not true for our class), on average, women do just as well on the untimed test. (Recall from a previous lab that the female average for our class on the untimed test was 1.5, while the male average was 1.89, and the female average for the timed test was 1.67, while the male average was 2.)

















    7. has a golden mean of (1+sqrt(5))/2 embedded in the forearm to hand ratio when rounded to one decimal value.

















    Major Writing Assignment for Statistics - A Persuasive Report

    Turn in the above sections (filled in) by the end of lab. This will be returned to you with feedback.
  • Write a persuasive report, convincing the reader that have found the "suspect" who satisfies all of the clues. The first draft of your writing assignment, worth 20% of this writing assignment's grade, is due Friday April 29th. You may work by yourself, or with at most one other person. Groups will be self-evaluated, and the evaluations will be taken into account for your final course average.
  • Your draft should have a cover page, a table of contents, the report, references and this packet (attached as an appendix). The references will be
    Greenwald, Sarah J, Math 1010 labs and private communication, 2001.
    Math 1010 class data, collected on 2/18/2002.
    Microsoft Excel software.
    and any other references that you use such as textbooks, help from other people, ...
  • Each of the clues should be a separatly labeled section in your report, with each section beginning by telling the reader what you will be presenting. You must also explain our data collection methods (see Math 1010 Data Collection Sheet), and the relevant statistics and methods that provide a convincing argument that this clue has been satisfied by your "suspect". Your explanation needs to convey deep understanding of the statistical methods involved.
  • In addition, your report needs to satisfy the writing checklist, which means (among other things) that it needs to have an introduction that introduces the major themes by summarizing what will be done in the paper.
  • Place the 4 graphs (accessible as links from this lab on the web - the bar graph, linear regression, histogram, and boxplot) into your paper into the relevant sections. To satisfy the checklist points regarding graphs, each graph needs to be placed in the text after the first time it is mentioned, and each graph must be fully explained.
  • You report is aimed at someone who does not know statistics. This means that you must explain in depth each statistical method (including a summary of how they are calculated and what they mean) and each graph (including what the graph shows on the x and y axes, how the data shown on the graph is obtained from the class data, how to read the graph, ...) used in your analysis.