Q:

Getting this error ! Extra }, or forgotten $. ... \sum_{i=1}^{N} \frac{{T}_{si}}{{T}_{ai}}}

I am getting this error 

! Extra }, or forgotten $. ... \sum_{i=1}^{N} \frac{{T}_{si}}{{T}_{ai}}}

for equation 
\begin{equation}
    SLATAH = \frac{1}{N} \sum_{i=1}^{N} \frac{{T}_{si}}{{T}_{ai}}}
\end{equation} 

can anybody help me?

A:

The last curly brace in
\begin{equation} SLATAH = \frac{1}{N} \sum_{i=1}^{N} \frac{{T}{si}}{{T}{ai}}} 

has no opening {. You should remove it.

