The Lab Report
 
 Experiment Title: Measuring Things Accurately
 
 Hypothesis: The length of the classroom can be measured accurately with a 
             short 6" ruler
 
 Materials: A 6" ruler, actually 17.28cm long
 
 Steps: 
 
   1. Make 12 groups of the 2 students from each table. 
 
   2. Each group is to measure the length of the room as accurately as possible.
      Don't tell anybody what you measure. Count the number of whole ruler
      lengths and the distance left over as accurately as possible. 
 
      Number of whole rulers _________  x  17.28 cm = _________ centimeters
 
      Remaining length in centimeters                 _________ centimeters
 
      Total length in centimeters                     _________ centimeters
 
   3. Write down all 12 measurements in order from smallest to largest. 
 
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 Computing the Results:
 
   1. What is the 6th largest measurement of the 12? This number is called the
      median...it is the middle number. 
 
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   2. Add up all 12 measurements and divide by 12. This number is called the
      average. 
 
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 Looking at the Results:
 
 Sometimes if we draw just the right picture we can understand things better.
 Numbers aren't always easy to understand. Your teacher will show you how to
 draw a scale from the smallest measurement to the largest, with the
 measurements marked on the scale with x's. Copy the drawing into your report
 and put x's where the numbers should be. Mark the median with an m, and mark
 the average with an a.
 
 
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 Thinking About the Results:
 
   1. Why are there so many different measurements? 
 
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   2. What do you think the length of the room really is? Why? Can anybody
      really tell?
 
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   3. Do you think any of the measurements are wrong because of a serious
      mistake? Why? Which ones?
 
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   4. If someone was to make still another measurement, what do you think it
      would be? Why? Would you be more certain if the measurements were
      grouped closer together?
 
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   5. Suppose one of the measurements was really far off. Would the median or
      the average be most affected by this error? Why?
 
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   6. Can you think of any ways to make more accurate measurements of the
      length of the room?
 
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