How do you find constant of proportionality? - Answers

You need to know the basic relationship between the variables: whether they are directly of inversely proportional to each other - or to a power of the other. Also, you need one scenario for which you know the values of both variables.So suppose you have 2 variables A and B and that A is directly proportional to the xth power of B where x is a known non-zero number. [If the relationship is inverse, then x will be negative.]Then A varies as B^x or A = k*B^xThe nature of the relationship gives you the value of x, and the given scenario gives you A and B. Therefore, in the equation A = k*B^x, the only unknown is k and so you can determine its value.