Originally Posted by pvaudio
Your example is true, but the OP is talking about probability. He says that you have a 40% success rate at something. That means the probability of you being successful is 40%. That is entirely different than you having been successful in 40% of your attempts as your example is stating. What you've said is what the OP is saying when he talks about a 40% average in a class being affected by getting a 50% on an assignment. That 40% is based on some prior successes and failures only. That is not the same thing as you being 40% likely to get a question right.
As you say, he says, "You have a 40% success rate." Does this mean that the intrinsic probability of success is 40% (you and Suresh). Or does it mean only that after a certain # of trials, he's logged a 40% success rate? (me).
In the context of everything else he says I think my interpretation makes sense, but let's ask the OP. OP! Is this about fractions or probability?
P.S. To the OP. What you say in the final paragraph is correct, i.e. a success has more weight b/c it is further from 40% than a fail. What's wrong with the earlier argument? It has its merits, but simply isn't the only factor.