1)

The regression equation:

y^= 4 + 1.2x

was calculated from a sample. It is part of a regression model that has been developed in order to predict the score in an end-of-year exam based on the score in a mid-year exam for a particular university course. In the sample, mid-year scores ranged from 50 to 72.

Select whether or not each of the following conclusions are correct from the regression analysis:

Correct or Not correct

a)For an increase by one in the mid-year score, the predicted increase in end-of-year score is 1.2.

b)If a student achieves a score of 45 in the mid-year exam then they will achieve a score of 58 in the end-of-year exam.

c)If a student achieves a score of 60 in the mid-year exam then they will achieve a score of 76 in the end-of-year exam.

-2

In simple linear regression, select the correct interpretation of the regression sum of squares(SSR):

A)SSR is the amount of variation in the response variable that is not accounted for by the explanatory variable.

B)SSR is the amount of variation in the explanatory variable that is accounted for by the response variable.

C)SSR is the amount of variation in the explanatory variable that is not accounted for by the response variable.

D)SSR is the amount of variation in the response variable that is accounted for by the explanatory variable.

-3

A simple linear regression equation is to be constructed to determine if there is a linear relationship between a response variable(Y)and an explanatory variable(X). A random sample of size n has been collected and the values x_iand y_ifori = 1, 2, ..., nhave been recorded. The residuals(e_i)in this analysis are defined as the difference between the observed values of Y and the values of Y predicted by the regression equation.

The scatterplot or residual plots can be used to see if the regression equation is an appropriate model for the data. An assumption required for the simple linear regression equation to be valid is:

A)X and Y are independent

B)the residuals are independent of one another

C)the residuals are constant

D)the variance of X is equal to the variance of Y