SOCR EduMaterials Activities Matching Juana oct10-06 version1

Quite often, a method used to solve a problem in probability can be used to solve many other problems which at first glance appear different, but are conceptually the same. This exercise illustrates this.

Go to the matching experiment in SOCR http://socr.stat.ucla.edu/htmls/SOCR_Experiments.html Run it several times and play with it until you feel comfortable with it. Then use it and interpret it appropriately to answer the following problems:

(1) Six students are working on a project for their Statistics class that requires a lot of calculations. Each of them is in charge of calculating one part of the project, but they all will share the results. As they work, they pass around the calculators so that everyone can see the results of the others. The smoke alarm sounds suddenly and each student grabs the nearest calculator and hurriedly leaves the room. What is the theoretical probability that none of the students too his or her calculator? What is the probability that you obtain from the data generated after repeating the correct experiment 1000 times? Attach a snapshot of the applet that shows how you found your answer with SOCR. (the snapshot should show the theoretical true probability and the probability you got by repeating this experiment 1000 times. Highlight what in the snapshot is your answer.

(2) 20 ladies arrive to a party and leave their coats with the concierge, who is not a very organized person. At the end of the party, the ladies don’t really remember what their coats look like (too much dancing and chocolate cake) and have lost the numbers the concierge give them. So the concierge has to give them the coats back at random. What is the theoretical probability that at least two ladies get their own coat? What is the probability that you obtain from the data generated after repeating the correct experiment 1000 times? Attach a snapshot of the applet that shows how you found your answer with SOCR. (the snapshot should show the theoretical true probability and the probability you got by repeating (appropriately) this experiment 1000 times. Highlight what in the snapshot is your answer.