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.
It is 30-60-90 triangle, so:

Answer B.
Answer:
6 3/10 pounds
Step-by-step explanation:
Answer:
CBC
Step-by-step explanation:
ez
<u>ANSWER</u>
The common ratio is -3.
<u>EXPLANATION</u>
In general, the common ratio of a Geometric Sequence is given by:

We can find the common ratio using any two consecutive terms of the geometric sequence by dividing the subsequent term by the previous term.
The given sequence is -2,6,-18,54
Using the first two terms the common ratio is

We could also used the second and third terms to get

and so on and so forth.
Therefore the common ratio is -3.