1. The problem statement, all variables and given/known data Find the interval of convergence for the given power series. Sum from n=1 to infinty of (x-11)^n / (n(-9)^n) 2. Relevant equations 3. The attempt at a solution I used the ratio test and I'm getting 2<x<20, but that doesn't seem to be right. I get abs(1/9*(x-11)) < 1, which simplifies into 2<x<20. I couldn't sworn I did this problem correctly, but I'm not getting the correct answer. Any help would be great.