Answer:
1. Cluster sampling
2. When finding a fair sample
3. Simple random sampling
What is the rest of the question??
Set up the proportion with the numbers on top equalling the cars and the numbers on the bottom representing the trucks.

c equals the number of unknown cars.
To solve the proportion, cross multiply (multiply 8 by 9 and 36 by c) and solve for c.
72 = 36c
Divide 36 from both sides to get the answer.
c = 2
If there are 9 trucks, there are 2 cars.
You can check this by dividing 2 by 9, and dividing 8 by 36. Since they both equal the same number, this answer is correct.
Hope this helps =)
Answer:
The 2 represents that each toppings costs $2.