Asked by Liz

Downs and Abwender (2002) found neurological deficits in soccer players who are routinely hit on the head with soccer balls compared to swimmers, who are also athletes but who are not regularly hit in the head. Is this an example of an experimental or a non-experimental study?

18) For the following scores, find the value of each expression:
a. _X
b. _X2
c. (_X)2
d. _(X _ 1)

X
4
2
1
5