Propensity interpretation
<img src=”http://www.google.com/chart?cht=tx&chf=bg,s,FFFFFF00&chco=000000&chl=e^z=\sum^{\infty}_{n=0}\frac{z^n}{n!}” />
<img src=”http://www.google.com/chart?cht=tx&chf=bg,s,FFFFFF00&chco=000000&chl=e^z=\sum^{\infty}_{n=0}\frac{z^n}{n!}” />