State Math SAT scores. Refer to the data on average state

QUESTION:

State Math SAT scores. Refer to the data on average state Math SAT scores for 2001 and 2011, Exercise 2.27 (p. 60). The first five observations and last two observations in the file are reproduced in the next table. In Exercise 2.126 (p. 105), you examined the relationship between the 2001 Math SAT scores and the 2011 Math SAT scores with a scatterplot.

Source: Based on “SAT Trends: Background on the SAT Takers in the Class of 2011.” The College Board.

a. Write the equation of a straight-line model relating 2011 Math SAT score (y) to 2001 Math SAT score (x).

b. An SPSS simple linear regression printout for the data is shown on the next page. Find the least squares prediction equation.

c. Give a practical interpretation of the y-intercept of the least squares line. If a practical interpretation is not possible, explain why.

d. Give a practical interpretation of the slope of the least squares line. Over what range of x is the interpretation meaningful?