A set of data consists of the number of years that applicants for Foreign Service jobs have studied German and the grades that they received on a proficiency test. The following regression equation is obtained: y-hat = 31.6 + 10.9x, where x is the number of years of study and y is the grade on the test. What does the slope of the regression line represent? а. The expected score on the test if a person had spent no years studying. b. The expected number of years studying if a person had scored a 0 on the test. C. We would expect grades on the test to increase 10.9 points for each additional year of study. d. We would expect additional years of study to increase by 10.9 years for each additional point on the test. е. What's a slope?

The given regression equation is y-hat=31.6+10.9x Where x is the number of years of study and y is the grade on the test. The positive value of slope depicts that the grade is expected to increase by 10.9 points as year increases one.Therefore, the correct answer is “Option c. We would expect grades on the test to increase 10.9 points for each additional year of study”.