Khan/khan-exercises — Issue #11974: Dependent probability - It's torture.
Author: KhanBugz
Created: 2012-01-24 04:31:48+00:00
State: open
Labels: hard, ie8, xp

Reporter: WynnSmith@gmail.com

I must have done nearly 50 problem questions on this probability page because .... why? It was torture. Over an hour of testing... why? How many problems did I do? The same ones over and over.... why? How many times did I calculate .5^2, or .5^3, or .5^4? over and over.... why? I hate your test page. It wasted my time. It was too picky. It didn't know the difference between .05 and 5%. When I calculated four digits of accuracy, it turned out I needed to calculate five digits and round to four. I must have gotten 20 consecutive correct answers and still it kept testing me. THE SOLUTION is: 1. Allow a conclusion after a sufficient number of consecutive correct answers are given, or 2. A sufficient percentage of correct answers, and make the result evaluator smarter so it knows the difference between .05 and 5%, and 4. it knows if the result is within the rounding bounds, in this case four digits. I can't imagine sending my students to this torture. I will not recommend your site to them.

[dependent_probability.html?seed=80&problem=0](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/dependent_probability.html?seed=80&problem=0&debug)

[Answer timeline](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/dependent_probability.html?seed=80&problem=0&debug&activity=%5B%5D)

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