Classified ads in the local paper offered several used model A cars for sale. Li
ID: 3240508 • Letter: C
Question
Classified ads in the local paper offered several used model A cars for sale. Listed to the right are the ages of the cars and the advertised prices. Complete parts a through f. a) Make a scatterplot for the data. Choose the correct graph below. b) Describe the association between year and price. A. There is a strong positive linear association between age and price of the model A cars. B. There is a weak positive linear association between age and price of the model A cars. C. There is a strong negative linear association between age and price of the model A cars D. There is a weak negative linear association between age and price of the model A cars. c) Do you think a linear model is appropriate? Yes No d) Computer software says that R^2 = 0.895. What is the correlation between age and price? The correlation, r, between Age and Price is (Round to three decimal places as needed.) e) Explain the meaning of R^2 in this context. A. Age accounts for 10.5% of the variation in advertised price. B. Age accounts for 89.5% of the variation in advertised price. C. Advertised price accounts for 89.5% of the variation in age. D. Advertised price accounts for 10.5% of the variation in age. f) Why doesn't this model explain 100% of the variability in the price of a used model A? A. It is impossible for "real world" data to be perfect B. There are not enough data points in the model. C. Other factors such as options, condition, and mileage contribute to the asking price. D. Different dealers ask different prices for cars of the same age.Explanation / Answer
Let,
X = Age
Y = Price advertised
x
y
1
1296510980
2
10475
3
1094010945
4
69857945
5
87206985
6
59704960
9
320022903995
11
29252935
13
1740
Question a)
Answer: Graph (A)
Question b)
Option B: There is a weak positive linear association between age and price of the model A cars.
Question c)
No
Question d)
r = sqrt(0.895) = 0.946
Answer: 0.946
Question e)
Option B: Age accounts for 89.5% of the variation in advertised price.
Question f)
Option C: Other factors such as options, condition and mileage contribute to the asking price.
x
y
1
1296510980
2
10475
3
1094010945
4
69857945
5
87206985
6
59704960
9
320022903995
11
29252935
13
1740