1. The problem statement, all variables and given/known data
As a lab experiment, we must try to measure and calculate the lifetime (τ) of a muon. After all data is collected, the lifetime can be calculate by using the maximum likelihood estimation.
The function on which MLE is applied:
http://j.imagehost.org/view/0139/Schermafbeelding_2010-04-27_om_22_29_38 [Broken]

One of the goals of this experiments is to do the MLE manually. For that I solved al the equations that are given by the definition of MLE. I finally ended with this equation:
http://j.imagehost.org/view/0926/Schermafbeelding_2010-04-27_om_22_29_56 [Broken]
T_{a}, T_{b} and N are constants, T_{i} is the dataset and Tau is the lifetime (this should be calculated).
I know this equation is correct. It should now be solved with mathematical software (I prefer matlab).

2. Relevant equations
My problem is to solve this in matlab. When i try to do this, it gives me the error:
"The expression to the left of the equals sign is not a valid target for an assignment."

3. The attempt at a solution
This is the code i used:

T_{i} is a variable with 61565 rows and one column