Statistics are characteristics that describe a sample of the population. In this case, 2% refers to the fraction of defective toys in the 500 toys sample, and not the whole population of toys.
Parameters, on the other hand, are characteristics that pertain to a population. The percentage of all toys that is defective would be a parameter.
Formulas are all unique and share the common trait of "x" and "y" values and a common purpose of helping you find the x and y value and/or answer to your question.