Quadratic function is definitely the key, not less than 10%.

Proportion is a mathematical term, which means that two or more equations are equal in proportion. In a proportion, the product of two external terms is equal to the product of two internal terms, which is called the basic property of proportion. In mathematics, if the change of one variable is always accompanied by the change of another variable, then these two variables are proportional. If these changes are always linked by a constant multiplier, then this constant is called a proportional coefficient or a proportional constant.