Consider the multiple regression model with two regressors x1 and x2, where both variables are determinants of the dependent variable y. you first regress y on x1 and find no relationship. however, while regressing y on x1 and x2 the slope coefficient of the variable x1 changes by a large amount. this suggests that your first regression suffers from: a. perfect multicollinearityb. dummy variable trapc. omitted variable biasd. heteroskedasticity

hello,

as   long as they add up to 180 its correct.

step-by-step explanation:

consider the parallelogram shown in the attached image.

in the parallelogram hijk, the length of hk is given as,

from the properties of parallelogram we know that the opposite sides of a parallelogram are parallel to each other and are equal in measure.

therefore, the length of the side ij must be equal to the length of the side hk and that is .

hence, the expression for the length of ij confirms that hijk is a parallelogram.

the first domain and range set to the left is matched with the top relation, and the second set the set in the middle goes with the bottom relation.