Catching Tic-Tacs

							                                Catching Tic-Tacs

The set-up

Everyone has tried to catch a piece of candy in his/her mouth after tossing it in the air.
However, does it make a difference if you throw it in the air, or a friend throws it at you?

REQUIREMENTS: 20 Tic-Tacs per participant. Participants should pair up.

You will be collecting 2 sets of data. One will consist of 10 trials where you will throw the
candy yourself (we will call this Data set A). The other set will consist of 10 trials where
your friend will throw the candy to you (Data set B). Remember, throw the Tic-Tacs
NICELY!!

1. To avoid bias due to “learning,” you should not all throw candy to yourself first. How could
you reduce the possibility of this bias?




2. We can use a 2-sample test where the 2 samples are collected independently from each
other or a paired test where each pair of samples has a common link. Explain which test you
are going to use and explain why you made your decision.




3. What is the parameter of interest?




4. What are the null and alternative hypotheses?

       H 0:



       HA:
Data collection & summary

5. Record the number (out of 10) that you catch with each method. Record the same
information for each of your classmates.

 Student        A          B        difference:         Student        A          B        difference:
    #                                d=A-B                 #                                d=A-B
    1                                                     16
    2                                                     17
    3                                                     18
    4                                                     19
    5                                                     20
    6                                                     21
    7                                                     22
    8                                                     23
    9                                                     24
   10                                                     25
    11                                                    26
   12                                                     27
   13                                                     28
   14                                                     29
   15                                                     30

6. Summarize the differences:



        n = __________                  d = __________                  s d = __________


Analysis and conclusions

7. Carry out a full hypothesis test at the α = 0.05 significance level and explain your
conclusion.