Question

3) Which of the following statements is TRUE about multiple regression?

I. We do not want our explanatory variables to be interrelated.
II. At least one slope should be statistically significant.
III. The slopes should not change if one variable is removed.

A) I only
B) II only
C) I and II only
D) I and III only

4) A regression model is built using the heights and body fat percentages to predict the weights of 30 volunteers. How many degrees of freedom for error does this model have?

A) 27
B) 3
C) 29
D) 30

Answer 1

3)A)I only

is the correct option since we donot want our explanatory variables to be interrelated ...and if they are interrelated then there will be presence of multicollinearity which we don't want.

3)B) C) D) options are incorrect since not always atleast one slope can be statistically significant and in multiple regression slope changes if one variable is removed , it is not changed only when it is Orthogonal model.

4)A) 27

Is correct option ,since n = 30 , two parameters are heights and body fat percentage so ...k=2 and 1 for intercept term ,hence (n-(k+1))= (30 -(2+1))= 27

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