The College Board, administrator of the SAT test for college entrants, has made several changes to the test in recent years. One recent change occurred between years 2005 and 2006. In a press release, the College Board announced SAT scores for students in the class of 2005, the last class to take the former version of the SAT featuring math and verbal sections. The board indicated that for the class of 2005, the average SAT math scores continued their strong upward trend, increasing from 518 in 2004 to 520 in 2005, 14 points above 10 years previous and an all-time high. The file titled MathSAT contains the math SAT scores for the interval 1967 to 2005.
a. Produce a scatter plot of the average SAT math scores versus the year the test was taken for all students (male and female) during the last 10 years (1996–2005).
b. Construct a regression equation to predict the average math scores with the year as the predictor.
c. Use regression to determine if the College Board’s assertion concerning the improvement in SAT average math test scores over the last 10 years is overly optimistic.