C. The way the sample was chosen may overrepresent or underrepresent students taking certain language classes.
The samples he chose may not be a representative sample because the number of students per foreign language class may not be the same. Since classes have different numbers of students, one may have a very large number of students while another may have only a few. Taking equal number of students per class is not a representative sample because it doesn't represent the students correctly.
Answer:
(a) 36
(b) y = 36x-31
Step-by-step explanation:
(a) dy/dx = 18x
slope of tangent at (2, 41) = 18(2)
= 36
(b) using y-y1 = m(x-x1)
y-41 = 36(x-2)
y = 36x-31