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.
1/10.
2/5 is equal to 4/10
4/10 divided by .4 is .1
so its 1/10
3·m - 2/3 - 2·m + 1/4 = 2/12
m - 2/3 + 1/4 = 2/12
m = 2/12 - 3/12 + 8/12
m = 7/12
Answer:
Center = (5,-3) radius = sqrt (36) = 6
Step-by-step explanation: