No entrepreneurs are risk averse would translate to:
RA-> ~E or E -> ~RA
Let's think about what this statement is saying - if someone is an entrepreneur, this person is NOT risk averse, where NOT risk averse is a necessary condition. Note how it is logically equivalent to:
RA - > ~E
If our necessary condition is no longer satisfied, then one is NOT an entrepreneur.
The fact that someone is NOT risk averse alone does not guarantee that he/she is an entrepreneur though, that is why it is not a sufficient condition.
The fact that on is an entrepreneur is sufficient to guarantee that this person is NOT risk averse even though it is not necessary for someone to be an entrepreneur to be risk averse.
Does this make sense? Let me know if you have any other questions.
