Chapter 9.4, Problem 3ES

For each given p-series, identify p and determine whether the series converges.

$\left(\text{a}\right){\displaystyle \underset{k=1}{\overset{\infty }{\sum }}\frac{1}{k^3}\left(\text{b}\right)}{\displaystyle \underset{k=1}{\overset{\infty }{\sum }}\frac{1}{\sqrt{k}}}\left(\text{c}\right){\displaystyle \underset{k=1}{\overset{\infty }{\sum }}{k}^{-1}}\left(\text{d}\right){\displaystyle \underset{k=1}{\overset{\infty }{\sum }}{k}^{-2/3}}$