Your Textbook Used the California Standardized Testing and Reporting (STAR)data

Your textbook used the California Standardized Testing and Reporting (STAR)data set
on test student performance in Chapters 4-7.One justification for putting second to
twelfth graders through such an exercise once a year is to make schools more
accountable.The hope is that schools with low scores will improve the following year
and in the future.To test for the presence of such an effect, you collect data from 1,000
L.A.County schools for grade 4 scores in 1998 and 1999, both for reading (Read)and
mathematics (Maths).Both are on a scale from zero to one hundred.The regression
results are as follows (homoskedasticity-only standard errors in parentheses): $$\begin{aligned}\widehat { \text { Math } _ { 99 } } = & 6.967 + 0.919 \text { Math } _ { 98 } , R ^ { 2 } = 0.825 , S E R = 7.818 \\& ( 0.542 ) ( 0.013 ) \\\\\widehat { \operatorname { Re } a d _ { 99 } } = & 4.131 + 0.943 \operatorname { Re } a d _ { 98 } , R ^ { 2 } = 0.887 , S E R = 6.416 \\& ( 0.409 ) ( 0.011 )\end{aligned}$$ (a)Interpret the results and indicate whether or not the coefficients are significantly different
from zero.Do the coefficients have the expected sign and magnitude?