This is my first time using the math mode. My problem is visible in the following screen capture. I find that the lower-case chi letter is rendered lower than the latin characters. Is that normal?

A test text and my relevant packages are below:
\documentclass[12pt,titlepage]{article}
\usepackage{setspace}
\setstretch{1.6}
\usepackage[final,babel]{microtype}
Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua: $\chi^{2} = 123.4567$ Ut enim ad minim veniam, quis nostrud exercitation ullamco labori nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
Thank you.
\gamma,\eta, and\mu.\phi\psi\zeta\xialso have descenders (not a complete list). Nothing to worry about. – Willie Wong Oct 3 '10 at 15:03