Don't guess i need to get this !
bob and his best friend bill have the same birthday, but bob is 3 years older than bill. let the variable x represent bob’s age and y represent bill’s age. which equation models the relationship between bill’s age and bob’s age?
a. y = x/3
b. y = x + 3
c. x = y + 3
d. y = 3x

Identify all the cases where non-probability sampling is used when attempting to study the characteristics of a large city. studies on every subject in the population divide a population in groups and obtain a sample studies with a limited amount of time demonstrate existing traits in a population studies with the nth person selected