F=9/5c+32 a is there a constant of proportionality? Explain your reasoning

yes because in a standard form that that equation is in, it'd be y=mx=b. the m represents the constant of proportionality or the rate of change. another name for it is the slope. in this case, the 9/5 is the m & c is x. meaning that, there is one & it is 9/5