NAME:                                                 :
Samples, written by Kay Somers, modified by Tom Linton
The goal of this activity is to introduce the notion of a simple random sample, and explore the notion of bias.
  1. On the last page of this handout are 100 rectangles of various sizes. Look at the page and make your best guess as to the average size of these rectangles. Record your guess below and then write it on the board as well.

    2.  

     

    Guess:                        .

  2. Now pick out 5 rectangles that you feel are representative. Record the number of each rectangle you picked and its area in the table below.
Rectangle
Number		          
Area          
  1. Compute and record the average area of the rectangles you picked                             .

    2.  

     
     
     

  2. Go to the random number table (Table B) in the back of your book. Pick a row and a column.

    3. Which row did you pick?              .
    Which column did you pick?             .
    Record ten digits (0 to 9) beginning at your chosen row and column (just keep reading digits in the next columns-rows as if the table were a book, but do NOT include the digits of the row numbers).
                       
  3. The random digits you picked will determine a set of five rectangles you will use to estimate the average area of all the rectangles shown. The first two digits give the number of your first rectangle. The third and fourth digits give the number of your second rectangle, etc. If the digits are 00, use rectangle number 100. Record the number of the randomly selected rectangles and their areas below.

    4.  
    Rectangle
    Number    		          
    Area          
  1. Compute and record the average area of the rectangles you picked                             .