A psychologist at the University of
California published a study in
which she claimed that college
students who prefer Polish
sausage react faster as compared
to college students who eat plain
hotdogs. She measured the time it
takes to respond when a stimulus,
a buzzer, is presented.
Here is a summary of the data:
Reaction Time ms
The difference between the two
means is 5 milliseconds. The
Polish sausage group responds in
less time, that is this group is
faster. However, a question pops
up: Is this difference reliable?
Which means, will we find this
difference, if we run the
experiment again, or this
difference was perhaps found by
chance.
We can use the normal distribution
to solve this problem. However, it
is the almost universal practice in
many sciences to use the t-test,
the so-called Student's t-test. The
t-test was created by William
Sealy Gosset.