A Set of Data Consists of the Number of Years $\hat { y } = 31.6 + 10.9 x$

Essay

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: $\hat { y } = 31.6 + 10.9 x$ where x represents the number of years of study and y represents the grade on the test. Identify the predictor and response variables.