Stats >> Training >> Stats #17: Practice Exercise

1. Your group should receive a package with the following:

• Two sheets of graph paper,
• A tape measure, and
• An object that you should push, toss, or flip.

Take five practice trials to push, toss, or flip your object so as to achieve the maximum distance and accuracy. While both distance and accuracy are important, accuracy (meaning consistency in the final location) should be your primary goal.

Now write down a standard operating procedure for how you will push, toss, or flip your object. Be sure to include enough detail so that someone who has not watched you will be able to reproduce your procedure. Here's an example of a procedure.

Coin flipping machine. Our group has a paper clip remover that has a plastic handle at one end and curved metal tip at the other end. A penny is placed on the plastic end with as much of the penny dangling over the edge as possible. The paper clip remover is aligned so that it is at the end of the table and perpendicular to the edge, with the plastic portion touching the edge of the table. We push down quickly on  the curved metal tip of the paper clip remover so as to cause the penny to flip up and over towards the other edge of the table. We measure the distance from the edge of the table to the final resting location of the penny in centimeters.

Depending on the particular object you have received you might want to measure the distance from the original location to the final resting spot or possibly the distance of the final resting spot from a target location.

Now run your procedure for pushing, tossing, or flipping at least 20 times and record the results on a sheet of paper. Here's an example of what that table would look like.

``` 1 61   6 20  11 26  16 38  2 14   7 20  12 44  17 18  3 20   8 21  13 85  18 53  4 62   9 14  14  8  19 34  5 30  10 48  15  4  20 23```

Now plot these values in sequence on your graph paper.

2. Interpret the chart that you just produced. Are there any obvious trends or patterns? Are there any outliers?

3. Review your standard operating procedure. Run an experiment where you vary the procedure and see what changes might improve the process. Use no more than 20 trials in your experiment.

4. Decide on two or three changes and rewrite your standard operating procedure. Collect data on 20 or more pushes, tosses, or flips and draw a second graph. Compare this graph to the first graph.