SATMathematics Practice Test 1

In the equation h=3a+28.6,if a, the age of the boy, increases by 1, then h becomes Therefore, the model estimates that the boy’s height increases by 3 inches each year
Alternatively: The height, h, is a linear function of the age, a, of the boy. The coefficient 3 can be interpreted as the rate of change of the function; in this case, the rate of change can be described as a change of 3 inches in height for every additional year in age.
Choices B, C, and D are incorrect and are likely to result from common errors in calculating the value of h or in calculating the difference between the values of h for different values of a.