A realtor used the regression model, y = beta0 + beta1x1 +beta2x2 + epsilon, to
ID: 3390702 • Letter: A
Question
A realtor used the regression model, y = beta0 + beta1x1 +beta2x2 + epsilon, to predict selling prices of homes (in thousands of $) in a region of California. The variable x1 represents the home size (square feet), and x2 represents the number of bedrooms.
ANOVA
Source DF SS MS F
Regression 2 6101.6
Error 219.6
Total 10
Coefficient Standard Error t statistic
Intercept 26.28 22.88 1.15
Size 0.12352 0.02435 5.07
Bedrooms 20.183 6.697 3.01
How many homes are included in the sample?
10
11
28
13
10
11
28
13
Explanation / Answer
The degrees of freedom is:
N-k-1=10 , where k= number of variables
N-3-1=10
N=10+4=14
But, if one has N data points then she can fit the points exactly with a polynomial of degree N-1.
Thus, the number of homes are included in the sample is 14-1=13