Find the radius of convergence for ∑n=1∞xnn⋅2n\sum_{n=1}^{\infty} \frac{x^n}{n \cdot 2^n}∑n=1∞n⋅2nxn using the ratio test.
R=1R = 1R=1
R=2R = 2R=2
R=12R = \frac{1}{2}R=21
R=∞R = \inftyR=∞