A school administrator believes that, in his school, the GPA of
seniors in their second semester is less than the GPA of seniors in
their first semester. The class size is large, so a census is not
practical because of time constraints. To test his belief, he selects a
SRS of senior GPA's from the first semester (n1 - 50) and an
independent SRS of senior GPA's from the second semester (n2-
50). He finds that x1 bar-3.1 and s1-0.8, and x2 bar.-2.8 and $2
-0.5. He defines p1 as the average GPA of seniors in semester 1
and u2 as the average GPA of seniors in semester 2.
The test of his belief for
statistical significance will be
a:
A. two-tailed test.
B. one-tailed left test.
C. one-tailed right test.