Math & Science ⇒ Bad math environment delimiter

[APOCooter]

Here is my MWE

Code: Select all

\documentclass[letterpaper]{article}  

\usepackage{amsmath}


\begin{document}


Using the invariance property of the MLE, we have:
\begin{align}
\begin{math}
\phi = f(\hat{\theta})Pr(Y_1 = 1) &= Pr(X_i > 0) \\
&= 1 - Pr(X_i < 0) \\
&= 1 - Pr(X_i - \theta< -\theta) \\
&= 1 - Pr(\frac{X_i - \theta}{1} < \frac{-\theta}{1}) \\
&= 1 - Pr(Z < -\theta) \\
&= 1 = Pr(Z < - \frac{\sum_{i=1}^n X_i}{n})
\end{math}
\end{align}

\end{document}

I have no idea why I'm getting the bad delimiter error. I don't think I have any extra or missing braces. I also removed \begin{math} and used $ around each individual argument that used math environment commands. I'm sure the fix is incredibly simple; however, I'm new to latex so I don't know what it is. Any help would be greatly appreciated.

[Johannes_B]

The environment align already switches to math-mode. Just comment out the math-environment.

Code: Select all

\documentclass{article}  
\usepackage{amsmath}
\begin{document}

Using the invariance property of the MLE, we have:
\begin{align}
\phi = f(\hat{\theta})Pr(Y_1 = 1) &= Pr(X_i > 0) \\
&= 1 - Pr(X_i < 0) \\
&= 1 - Pr(X_i - \theta< -\theta) \\
&= 1 - Pr(\frac{X_i - \theta}{1} < \frac{-\theta}{1}) \\
&= 1 - Pr(Z < -\theta) \\
&= 1 = Pr(Z < - \frac{\sum_{i=1}^n X_i}{n})
\end{align}
\end{document}

Once again, thank you for the nice minimal example. That already made my day.

Best regards
Johannes

PS: if you have a single letter exponent or index, you don't need curly braces, but if you always set them, you will (most likely) never get in trouble.
\sum_{i=1}^{n}
Just as a small tip.