I believe it is D, stratified random sampling.
Hope this helps!!
Answer:
1st box: Asso. prop= m+(4+x)
2nd box: Comm. Prop= m+4=4+m
3rd box: iden. prop= m+0=m
4th box: Zero prop: m x 0=0
Answer:
true
Step-by-step explanation:
Answer:

Step-by-step explanation:

Subtract 7 from both sides.

Multiply both sides by v.

Multiply both sides by 1/(y - 7).

Answer:
20 points
Step-by-step explanation:
Points:
- 21, 13, 14 and x for the last game
Average:
- (21+13+14+x) / 4 = 17
- 48 + x = 4*17
- 48 + x = 68
- x = 68 - 48
- x = 20
They must score 20 points