ummmm it could be third one i guesss
Answer:

Step-by-step explanation:

This is not a random sample since she is outside of a pet store and the probability of people owning a dog coming out of that store is very very high. If she went around the neighborhood and knocked on people’s door and asked if they had a dog or not would be random sample.
Answer:
Rate of change = 0.5
Initial value = 120
Step-by-step explanation:
(10 , 125) ; (30 , 135)
Slope = 

Rate of change = 0.5
Initial value = 120