求救...趕功課~唔識statistics...身在外國,沒人教路~(4)

HY Law

2007-04-01 7:01 am

c)Computer software says that r2(square) = 0.894. What is the correlation between age and price? Explain the meaning of r2(square) in this context.[3 Marks]
d)Why doesn’t this model explain 100% of the variability in the price of a used Corolla?[2 Marks]

回答 (1)

myisland8132

2007-04-01 8:36 pm

✔ 最佳答案

(c)

correlation between age and price
=squareroot[r2(square)]
=squareroot[0.894]
=0.9455
r2(square) in this context measures that 89.4% variation in the price of the car can be explained by the variation in the age of the car.
(d)
Because except age there are still some other factors that will effect the price of the car . For example if there are two man both have a car with 10 years old. Man A always use his car while the other man B does not and check, maintain his car every year. Then man B may think that his car is more valuable and so ask a higher price.
So only age cannot explain 100% of the variability in the price of a used Corolla?

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