Khan/khan-exercises — Issue #14458: Dependent probability - Answer is rounded improperly
Author: KhanBugz
Created: 2012-02-23 00:16:46+00:00
State: open
Labels: firefox, win7, wrong-or-unclear

"You have 13 coins in a bag. 3 of them are unfair in that they have a 40% chance of coming up heads when flipped (the rest are fair coins). You randomly choose one coin from the bag and flip it 4 times.

What is the probability, written as a percentage, of getting 4 heads? Round your answer to the nearest hundredth of a percent."

The answer should be 5.39%, but instead is rounded to 5.4% when the question says to round to the nearest hundredth, not the nearest tenth.

[dependent_probability.html?seed=151&problem=0](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/dependent_probability.html?seed=151&problem=0&debug)

[Answer timeline](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/dependent_probability.html?seed=151&problem=0&debug&activity=%5B%5B%22incorrect-activity%22%2C%22%5C%225.39%25%5C%22%22%2C43%5D%2C%5B%22hint-activity%22%2C%220%22%2C3%5D%2C%5B%22hint-activity%22%2C%220%22%2C4%5D%2C%5B%22hint-activity%22%2C%220%22%2C5%5D%2C%5B%22hint-activity%22%2C%220%22%2C5%5D%2C%5B%22hint-activity%22%2C%220%22%2C6%5D%2C%5B%22hint-activity%22%2C%220%22%2C7%5D%2C%5B%22hint-activity%22%2C%220%22%2C7%5D%2C%5B%22hint-activity%22%2C%220%22%2C8%5D%2C%5B%22hint-activity%22%2C%220%22%2C21%5D%2C%5B%22hint-activity%22%2C%220%22%2C22%5D%2C%5B%22hint-activity%22%2C%220%22%2C24%5D%2C%5B%22hint-activity%22%2C%220%22%2C25%5D%2C%5B%22correct-activity%22%2C%22%5C%225.4%25%5C%22%22%2C47%5D%5D)

["5.39%","5.4%"]

Mozilla/5.0 (Windows NT 6.1; WOW64; rv:11.0) Gecko/20100101 Firefox/11.0

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