Khan/khan-exercises — Issue #14935: Variance - Variance
Author: KhanBugz
Created: 2012-02-29 10:22:11+00:00
State: open
Labels: firefox, wrong-or-unclear, xp

Reporter: Mackspower75@gmail.com

The variance questions need to state that the average age "must" be rounded to the nearest 1/10. Right now it says "may" be rounded to the nearest 1/10 but on a question such as the one I just did, and a few others, where instead of rounding the average age to 1.8 I used the more accurate 1.75 my answer is being registered wrong when it is actually more accurate. 1.8 ends up with a variance of .25 whereas the more accurate 1.75 has a variance of 0 with the result being the more accurate answer is marked wrong. A suggestion would be to increase the +/_ to .25 from the current .15 or clarifying that the average age "must" be rounded to the nearest 1/10.

[variance.html?seed=124&problem=sample](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/variance.html?seed=124&problem=sample&debug)

[Answer timeline](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/variance.html?seed=124&problem=sample&debug&activity=%5B%5B%22incorrect-activity%22%2C%22%5B%5C%221.75%5C%22%2C%5C%220%5C%22%5D%22%2C341%5D%2C%5B%22hint-activity%22%2C%220%22%2C1%5D%2C%5B%22hint-activity%22%2C%220%22%2C2%5D%2C%5B%22hint-activity%22%2C%220%22%2C2%5D%2C%5B%22hint-activity%22%2C%220%22%2C2%5D%2C%5B%22hint-activity%22%2C%220%22%2C3%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%2C4%5D%2C%5B%22hint-activity%22%2C%220%22%2C4%5D%5D)

[["1.75","0"]]

Mozilla/5.0 (Windows NT 5.1; rv:10.0.2) Gecko/20100101 Firefox/10.0.2

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