1. The problem statement, all variables and given/known data A variable star changes in brightness by a factor of 4. What is the change in magnitude? 2. Relevant equations m and n represent two stars of magnitude m-n=2.5 log(f(n)/f(m)) log (f(n)/f(m))=.4*(m-n) 3. The attempt at a solution I think m-n is suppose to represent a change in magnitude.perhaps a factor of 4 = log(f(n)/f(m) . Therefore , m-n=2.5*4=10 ?