1. Suppose we developed the following least squares regression equation: Y = 3.5 + 2.1X. Which of the following statements are correct?
A.The dependent variable increases 2.1 for an increase of 1 in X.
B.The regression line crosses the Y-axis at 3.5.
C.If X = 5, then Y = 14.
D.All of the above.
2. The least squares regression equation was computed to be y = 16.1 - 6.7X. The coefficient of correlation r is
A.a positive value
B.a negative value
C.either a positive or a negative value
D.zero
E.none of the above
2. The mayor believes that there are differences of opinion among the officials of different counties about expansion of public transportation in the state. Therefore, the mayor has decided to take a sample of the officials for interview, and has planned to select a random sample of officials from each county in the state. This is an example of a
A.Simple random sample
B.Cluster sample
C.Stratified random sample
D.Systematic sample
E.Convenience sample
4. The slope of a regression equation is 10, the value where the line intersects the Y axis when X = 0 is 4. What is the regression equation?
A.X = 0 + 10Y
B.Y = 10- 4X
C.Y = 4 + lOX
D.Y = 4- lOX
E.none of the above