1. The problem statement, all variables and given/known data Find interval of convergence and radius of convergence of the following infinite series. Series from n=1 to infinity ((-3)^n * x^n) / (n*(n)^1/2) 2. Relevant equations Ratio test 3. The attempt at a solution I've started with the ratio test and end up getting 3xn^(3/2) / (n+1)^(3/2) after cancellation. I don't know how to cancel anything else out, I'm guessing L'Hopital's rule but that doesn't seem right. I feel like I should be able to do more cancellation here.