Final answer:
The slope of the model y=0.48x+59.58 is 0.48. This indicates an average test score increase of 0.48 points for each additional minute of studying.
Step-by-step explanation:
The equation given is y=0.48x+59.58, which models the relationship between minutes spent studying (x) and the test score earned (y). To find the slope of this equation, we look at the coefficient of the x term. In the standard slope-intercept form of a line, y = mx + b, the slope is represented by m. Here, the coefficient of x is 0.48, which means that this is the slope of our linear model. This slope signifies that for every additional minute spent studying, the test score increases by an average of 0.48 points.