Question

for the 150 cars on the lot of a used - car dealership, explain why you would expect a positive relationship, negative relationship, or no relationship between the pairs of variables in parts a through e.
a. consider the age of the car and the number of oil changes. what would one expect to be the relationship between the variables?
a. no relationship because the number of oil changes is not correlated with the age of the car
b. positive relationship because the number of oil changes decreases as the age of the car increases
c. positive relationship because the number of oil changes increases as the age of the car increases
d. negative relationship because the number of oil changes increases as the age of the car increases
b. consider the age of the car and the years of life remaining. what would one expect to be the relationship between the variables?
a. positive relationship because the years of life remaining decreases as the age of the car increases
b. negative relationship because the years of life remaining decreases as the age of the car increases
c. no relationship because the years of life remaining is not correlated with the age of the car
d. positive relationship because the years of life remaining increases as the age of the car increases

Explanation:

a. As a car gets older, more time has passed during which oil - changes are likely to occur, so the number of oil - changes is expected to increase with the age of the car, indicating a positive relationship.
b. As the age of a car increases, the remaining useful life of the car generally decreases, which shows a negative relationship between the age of the car and the years of life remaining.

Answer:

a. C. Positive relationship because the number of oil changes increases as the age of the car increases
b. B. Negative relationship because the years of life remaining decreases as the age of the car increases