Final answer:
In the equation f(60) = 63.7, '60' is the independent variable because it is the input to the function, and 'f' is the dependent variable as it is the output that depends on 60.
Step-by-step explanation:
In mathematics when dealing with functions and equations, the independent variable is the input of the function, which is freely selected, whereas the dependent variable is the output of the function, which depends on the independent variable. Given the equation f(60) = 63.7, '60' is the independent variable because it represents the input to the function f. The dependent variable is represented by f itself, as it is the value that depends on the independent variable. Therefore, the correct option is a) Independent variable: 60; Dependent variable: f.