The State of Virginia has instituted a series of standards of learning (SOL) tests in math, history, English, and science that all high school students must pass with a grade of 70 before they are allowed to graduate and receive their diplomas. The school superintendent of Montgomery County believes the tests are unfair because the test scores are closely related to teacher salary and tenure (i.e., the years a teacher has been at a school). The superintendent has sampled 12 other county school systems in the state and accumulated the following data for average teacher salary and average teacher tenure:

School Average SOL Score Average Teacher Salary Average Teacher Tenure (yr.)

1 81 $34,300 9.3 2 78 28,700 10.1 3 76 26,500 7.6 4 77 36,200 8.2 5 84 35,900 8.8 6 86 32,500 12.7 7 79 31,800 8.4 8 91 38,200 11.5 9 68 27,100 8.3 10 73 31,500 7.3 11 90 37,600 12.3 12 85 40,400 14.2

a. Using Excel or QM for Windows, develop the multiple regression equation for these data.

b. What is the coefficient of determination for this regression equation? Do you think the superintendent is correct in his beliefs?

c. Montgomery County has an average SOL score of 74, an average teacher salary of $27,500, and an average teacher tenure of 7.8 years. The superintendent has proposed to the school board a salary increase that would raise the average salary to $30,000 as well as a benefits program, with the goal of increasing the average tenure to 9 years. He has suggested that if the board passes his proposals, then the average SOL score will increase to 80. Is he correct, according to the forecasting model? LO.1